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SARS-CoV-2 Vaccination During Pregnancy: A Complex Decision

SARS-CoV-2 Vaccination During Pregnancy: A Complex Decision Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 1 2 3 3,4,* Elizabeth Wenqian Wang, Jacqueline G. Parchem, Robert L. Atmar , Eva Clark Department of Infectious Diseases, University of Maryland St. Joseph Medical Center, Towson, MD, USA Department of Obstetrics, Gynecology and Reproductive Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, TX, USA Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA Department of Medicine, Section of Health Services Research, Center for Innovations in Quality, Safety, and Effectiveness (IQuESt), Michael E. DeBakey VA Medical Center and Baylor College of Medicine, Houston, TX, USA *Corresponding author: Eva Clark, eva.clark@bcm.edu, (713) 440-4400 (phone), (713) 748-7359 (fax), Houston HSR&D Center for Innovations in Quality, Effectiveness, and Safety (IQuESt) Baylor College of Medicine Michael E. DeBakey VA Medical Center, 2450 Holcombe Blvd., Suite 01Y, Houston, TX 77021, USA Conflict of Interest Statement: No authors report any conflicts of interest. Patient Consent Statement: None needed as no individual patients are mentioned in this article. Published by Oxford University Press on behalf of Infectious Diseases Society of America 2021. This work is written by (a) US Government employee(s) and is in the public domain in the US. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Abstract:As the first Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines passed United Kingdom and United States regulatory milestones in late 2020 and early 2021, multiple professional societies offered recommendations to assist pregnant and breastfeeding people as they choose whether to undergo vaccination. Despite such guidance, the lack of data describing vaccine safety, immunogenicity, and efficacy in pregnant and breastfeeding people has made this decision challenging for many. However, even considering the paucity of data, the known risks of Coronavirus Disease 2019 (COVID-19) during pregnancy likely outweigh the not yet fully elucidated risks of SARS-CoV-2 vaccines, which have reassuring safety and efficacy profiles among non-pregnant people. Keywords: SARS-CoV-2, COVID-19, vaccine, pregnancy, breastfeeding Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Essential workers and high-risk individuals in the United Kingdom and the United States began receiving doses of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines en masse as the first vaccine candidates obtained emergency use authorization in December 2020. While the safety, immunogenicity, and efficacy data for the four authorized vaccines are reassuring so far [1- 4], none of these vaccines has been systematically studied in pregnant and breastfeeding people, despite evidence that pregnancy may increase the risk of developing severe Coronavirus Disease 2019 (COVID-19) and related complications. In the United States, approximately 10% of pregnant people with COVID-19 have severe or critical illness [5, 6], and their in-hospital mortality is significantly higher compared to non-pregnant people of similar age [7]. The decision of whether to undergo SARS-CoV-2 vaccination during pregnancy is complex and causes apprehension among those considering vaccination [8]. Here, we discuss the risks and benefits of SARS-CoV-2 vaccination in pregnancy that may influence the decision-making process. Risk of pregnancy complications due to SARS-CoV-2 infection It is unclear whether pregnant people are more susceptible to SARS-CoV-2 infection than non- pregnant people. Many pregnant people infected with SARS-CoV-2 are asymptomatic (ranging from 44 to 86% in cohort studies with universally tested pregnant populations [9-11]). While the risk of mortality is low and comparable to that of the nonpregnant population (0.1-0.2%), preexisting comorbidities, higher maternal age, and higher body mass index are risk factors for severe COVID-19 in pregnancy [12-15]. Pregnant people who develop COVID-19 are more likely to require intensive care and have severe cardiopulmonary complications than their nonpregnant counterparts [13, 15, 16] (though these studies had several limitations; for instance, in the US Centers for Disease and Prevention [CDC] reports, pregnancy status and information on symptoms and underlying conditions were missing from more than 50% of cases [13, 15]). One retrospective evaluation of a large US cohort of hospitalized pregnant patients found that in-hospital mortality was significantly higher in those with COVID-19 compared to those without COVID-19 (141 [95% CI, 65-268] versus 5.0 [95% Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 CI, 3.1-7.7] deaths per 100,000 women) [7]. Additionally, some studies have suggested that pregnant people with COVID-19 have an increased risk of delivering premature and/or low birthweight infants, post-partum hemorrhage, and complications requiring caesarean delivery [10, 11, 17-19]. Vertical transmission of SARS-CoV-2 certainly occurs (both in utero, which is uncommon, and peripartum), though infected infants tend to have asymptomatic disease or only mild symptoms [20, 21]. Furthermore, pregnant people who develop COVID-19 in low resource settings – where pregnancy outcomes are already poorer due to prevalent comorbidities, coinfections, and socioeconomic and health system inequalities – often lack access to effective medications and high levels of supportive care [22, 23]. Exclusion of pregnant people from SARS-CoV-2 vaccine trials has resulted in limited data describing vaccine safety and efficacy in pregnancy Exclusion of pregnant people from vaccine trials has been an longstanding problem [24]. Their exclusion has resulted in vaccine recommendations for pregnant women based on little data (e.g., as for the initial recommendations for inactivated influenza vaccines [25], though subsequently robust clinical trials supported these recommendations) or recommendations only being given once “enough” pregnant people have been inadvertently vaccinated (e.g., as for MenAfriVac, a meningococcal A conjugate vaccine [26]). Since 2018, both governmental and independent advisory groups have published recommendations advocating for the early inclusion of pregnant people in the development and deployment of vaccines against emerging pathogens [27, 28]. Subsequently, during the rapid emergence of SARS-CoV-2, many authorities advocated for inclusion of pregnant people in SARS- CoV-2 vaccine trials [29, 30]. Despite this expert guidance and the potentially devastating consequences of SARS-CoV-2 infection, pregnant people were explicitly excluded from SARS-CoV- 2 vaccine clinical trials. Consequently, to date there are little published data describing the safety or efficacy of any SARS-CoV-2 vaccine in human pregnancy. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 SARS-CoV-2 vaccine platforms authorized in the UK and US and their potential risks Historically, protein-based vaccines (which are non-replicating) have been considered safe in pregnancy, for both mother and fetus. In fact, the CDC’s Advisory Committee on Immunization Practices (ACIP) recommends routine influenza and Tdap vaccination of all pregnant women as these vaccines are safe and induce maternal antibodies that are passed to the child in utero and via breastfeeding, thereby protecting the child from the diseases targeted by these vaccines [31]. As of March 15, 2021, four SARS-CoV-2 vaccines have gained regulatory authorization either in the UK or the US, including the Pfizer/BioNTech, Moderna/NIH, Oxford/AstraZeneca, and Janssen vaccines. While all four authorized SARS-CoV-2 vaccines are non-replicating vaccines, they are based on relatively new vaccine technology. Both the Pfizer/BioNTech and Moderna/NIH vaccines are messenger RNA (mRNA) nanoparticle-based platforms encoding the SARS-CoV-2 spike protein that require two doses spaced three to four weeks apart [32, 33]. The Oxford/AstraZeneca and Janssen vaccines are replication-deficient adenovirus vector vaccines containing spike protein DNA [34, 35]. The Oxford/AstraZeneca vaccine also requires two doses, while the Janssen vaccine is authorized for use as a single dose vaccine. In contrast to conventional protein-based vaccines, these nucleic acid- based vaccines provide genetic blueprints that allow the recipient’s own cells to produce the target antigen. Theoretical concerns have been suggested regarding the potential for host genome insertion and mutagenesis of vaccine genetic material. However, these concerns are unsubstantiated by scientific evidence; the SARS-CoV-2 genetic material carried by these vaccines is not infectious, does not incorporate into the recipient’s genome, and levels of vaccine mRNA/DNA and associated protein decline over several days post-vaccination as they are degraded by normal host cellular processes [36, 37]. Research on nanoparticle and adenovirus-vectored vaccines has been ongoing for decades [36, 37]. Specifically, human adenovirus serotype 26 (Ad26, which is the Janssen vaccine vector) has been used as a vector for other vaccines deemed safe for the general public, including the Ad26.ZEBOV/MVA-BN-Filo Ebola vaccine that was approved in Europe in 2020, as well as investigational vaccines against Zika, filovirus, HIV, HPV, malaria, and respiratory syncytial virus. No adverse pregnancy outcomes have been reported for these vaccines. However, the current COVID- Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 19 pandemic era is the first time that these vaccine types are being widely distributed among the general population. Though pregnant individuals were excluded from initial clinical trials of the four vaccines authorized to date, these trials do provide information on adverse effects unrelated to pregnancy, which are important for pregnant people to consider prior to vaccination. In these trials, reports of serious adverse effects were rare (most notably, three cases of transverse myelitis were reported during the AstraZeneca/Oxford vaccine clinical trials but were thought unlikely to be related to the vaccine after independent safety committee review [38]). Short-lived, mild to moderate adverse reactions are common after vaccination with all four of the SARS-CoV-2 vaccines discussed here. For the mRNA vaccines, the most common adverse reactions were injection site reactions (84.1% for the Pfizer/BioNTech vaccine, 91.6% for the Moderna/NIH vaccine), fatigue (62.9%, 68.5%), headache (55.1%, 63.0%), muscle pain (38.3%, 59.6%), chills (31.9%, 43.4%), joint pain (23.6%, 44.8%), and fever (14.2%, 14.8%) [32, 33]. Local injection site reactions, fatigue, headache, fever, and muscle pains also were common for the Oxford/AstraZeneca [34] and Janssen vaccines (for which the most common adverse reactions were injection site pain [48.6%], headache [38.9%], fatigue [38.2%], and myalgia [33.2%] [35]). Whether such adverse effects are associated with any risks to the mother or fetus is unclear. Of the four vaccines discussed here, Pfizer/BioNTech, Moderna/NIH, and Janssen have completed pre- clinical developmental and reproductive toxicity (DART) studies; none found any adverse effects on animal reproduction or fetal development. Regarding human data, small numbers of pregnant people were inadvertently enrolled during vaccine clinical trials (23, including 12 in the vaccine arm, for the Pfizer/BioNTech vaccine [32]; 13, including six in the vaccine arm, for the Moderna/NIH vaccine [33]; and eight, including four in the vaccine arm, for the Janssen vaccine [35]). Oxford/AstraZeneca has not yet publicly disclosed information on whether pregnancies were reported during their clinical trials. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Ongoing and planned SARS-CoV-2 vaccine evaluations in pregnant populations Though the small numbers of pregnant people discussed above were inadvertently enrolled in the SARS-CoV-2 vaccine clinical trials, the information generated by their follow-up is unlikely to provide conclusive evidence regarding vaccine safety or efficacy. Because pregnancy poses unique safety concerns, it is essential that pregnant people are included in appropriately designed vaccine trials. Pfizer recently announced that they will perform a global Phase 2/3 trial to evaluate the safety, tolerability and immunogenicity of SARS-CoV-2 vaccine in pregnant people who are 18 years and older [39]. The trial is a randomized, placebo-controlled, observer-blind study of 4,000 healthy women vaccinated between 24 to 34 weeks of gestation. Each woman will participate in the study for seven to ten months, depending on whether randomized to receive vaccine or placebo, and their infants will be monitored to six months of age. Moderna has created a registry of pregnant vaccinees and is planning a prospective observational study to assess obstetric, neonatal, and infant outcomes [40]. Janssen is planning a phase 2 placebo-controlled trial in more than 800 pregnant people [41]. AstraZeneca’s plans for clinical trials in pregnant people are still uncertain. It is important that these trials move forward to evaluate the remaining unknown issues related to pregnancy such as vaccine safety and immunogenicity (including rates of antibody transfer to neonates). However, potential problems with this delayed approach to inclusion of pregnant people in vaccine clinical trials include (1) data are unavailable for pregnant people otherwise eligible for vaccination now, obligating reliance on observational data; (2) potential low trial enrollment if pregnant people do not want to risk being in the placebo arm; and (3) the resultant trial sample size may be too small to detect differences in perinatal outcomes. Additionally, the CDC has established a voluntary smartphone-based registry for SARS-CoV-2 vaccine recipients called “v-safe,” which includes both a post-vaccination “health checker” and a registry of pregnant people; as of March 15, 2021, more than 50,000 pregnant people were enrolled in Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 this monitoring program [42]. So far, v-safe data indicate no safety issues. Most adverse events (73%) reported were not related to pregnancy. Of the pregnancy-related adverse events, miscarriage was reported most frequently (in 29 participants); however, the reported miscarriage numbers reflect background rates [43]. The UK Medicines and Healthcare Products Regulatory Agency (MHRA) has a similar post-vaccination registry and has also found no safety concerns in pregnant people during their data analysis [44]. Public health and personal advantages of SARS-CoV-2 vaccination of pregnant and breastfeeding people The obvious advantage to SARS-CoV-2 vaccination is protection of pregnant people – and, to some extent, their neonates – from the potentially devastating complications of SARS-CoV-2 infection. In non-pregnant populations, the efficacies reported for the authorized SARS-CoV-2 vaccines are 95.0% for the Pfizer/BioNTech vaccine [32], 94.1% for the Moderna/NIH vaccine [33], 70.4% for the Oxford/AstraZeneca vaccine (notably, this percentage is derived from pooled analysis of groups that received different vaccine doses [38]), and 66.9% for the Janssen vaccine [35]. Efficacies are likely to be similarly robust in pregnant populations. Prospective studies have already described SARS-CoV-2 vaccine-induced immune responses in pregnant and lactating people, with even higher antibody titers than those induced by SARS-CoV-2 infection during pregnancy [45]. From a public health perspective, broad vaccine uptake (i.e., an estimated 55-82% of the population) is needed to achieve effective population immunity [46], which undoubtedly will take some time. Vaccinating as many people as possible, including pregnant and breastfeeding people, will help attain such levels more quickly. Finally, many essential workers, particularly those who are currently pregnant, have anxiety about acquiring SARS-CoV-2 infection and transmitting the virus to family, patients, and co-workers [8]; vaccination would likely ameliorate these anxieties and provide welcomed relief and peace of mind for many. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Impact of SARS-CoV-2 vaccination on fetuses and breastfeeding infants While mRNA nanoparticle and adenovirus vector SARS-CoV-2 vaccines are not thought to pose significant risk to the recipient’s fetus, important questions regarding fetal risk are only beginning to be answered [47, 48]. For instance, whether intact vaccine particles cross the placenta and enter fetal cells remains largely unknown, though studies of other lipid nanoparticle platforms suggest that they do not cross to the fetus [49]. The publication of pre-clinical DART study data and small human studies are helping to clarify such issues. For instance, one study evaluated six women after receipt of mRNA-based vaccines (five received Pfizer/BioNTech and one received Moderna/NIH) and found no evidence of vaccine mRNA in breast milk samples collected within two days of vaccination [50]. Regarding whether maternal SARS-CoV-2 immunization leads to transfer of specific antibodies to infants, one study of 20 mother-infant pairs demonstrated efficient transplacental transfer of anti- SARS-CoV-2 spike antibodies after antenatal vaccination with the Pfizer/BioNTech vaccine [51], and another showed presence of vaccine-derived IgA antibodies in breastmilk three to four weeks post- vaccination with the Pfizer/BioNTech (n=14) and Moderna (n=9) vaccines [52]. In the latter study, IgA antibody titers in breastmilk were similar to those of participants who had experienced natural SARS-CoV-2 infection. Such findings should encourage vaccination of breastfeeding people, among whom any theoretical risks related to vaccination are likely the same as those of the general population. Additionally, both Pfizer and Moderna are conducting clinical trials of their vaccines in children, and Janssen plans to start clinical trials in adolescents in March 2021, which will yield needed data on the safety, immunogenicity, and efficacy in these populations. Regulatory and professional body guidance on SARS-CoV-2 vaccination in pregnancy The paucity of data on SARS-CoV-2 vaccines in pregnant and breastfeeding populations makes counseling patients challenging. Many regulatory agencies in the UK and the US have made Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 recommendations regarding SARS-CoV-2 vaccination in pregnancy (Table 1). Advisory bodies in the UK, such as the MHRA and the Royal College of Obstetricians and Gynaecologists (RCOG) initially advised against offering SARS-CoV-2 vaccines to people who are pregnant and breastfeeding, due to lack of safety data in these populations [53], but updated their positions on December 30, 2020 [54], to recommend consideration of vaccination in those who are frontline personnel or those who have underlying conditions that make them high risk of being infected with or experiencing serious complications of COVID-19, which includes pregnancy [54]. In contrast, the CDC’s ACIP advises allowing all pregnant and breastfeeding people to choose whether to be vaccinated [21], and, in the CDC’s recommendations for prioritization of SARS-CoV-2 vaccine allocation, pregnancy is included as a “high risk” condition eligible for vaccination during Phase 1C [55]. Multiple reproductive medicine organizations, including the American College of Obstetricians and Gynecologists (ACOG), the Society for Maternal-Fetal Medicine (SMFM), the American Society for Reproductive Medicine (ASRM), and the Academy of Breastfeeding Medicine (ABM), agree that SARS-CoV-2 vaccines should not be withheld from pregnant and breastfeeding people who are otherwise eligible [56]. Clearly, with all the above data (and lack thereof) and factors to consider, the decision of whether to undergo SARS-CoV-2 vaccination during pregnancy or while breastfeeding is a complex one. Healthcare provider counselling of pregnant people should focus on the available vaccine safety and efficacy data in the context of the individual’s personal risk of SARS-CoV-2 exposure, underlying medical conditions, and SARS-CoV-2 prevalence in the community. Several of the advisory bodies mentioned have published guides for counselling pregnant and lactating people as they contemplate the pros and cons of vaccination (e.g., a “conversation guide” from ACOG can be found here: https://www.acog.org/- /media/project/acog/acogorg/files/pdfs/clinical-guidance/practice-advisory/covid19vaccine- conversationguide-121520-v2.pdf?la=en&hash=439FFEC1991B7DD3925352A5308C7C42, and SMFM provides “Provider Considerations for Engaging in COVID-19 Vaccine Counseling Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 With Pregnant and Lactating Patients” here: https://s3.amazonaws.com/cdn.smfm.org/media/2838/Provider_Considerations_for_Engaging_in_CO VID_Vaccination_Considerations_3-3-21_(final).pdf). Conclusions Because pregnant people were explicitly excluded from SARS-CoV-2 vaccine clinical trials, little data are available to guide them as they decide whether to undergo SARS-CoV-2 vaccination. Even so, given the reassuring safety and efficacy profiles of the SARS-CoV-2 vaccines that have gained UK/US regulatory authorization to date, the known risks of COVID-19 likely outweigh the unclear risks of SARS-CoV-2 vaccines for pregnant and breastfeeding people. Going forward, every effort should be made to collect data on the safety, immunogenicity, and efficacy of SARS-CoV-2 vaccines in pregnant and breastfeeding people through well-designed clinical trials that include these populations. As a matter of expediency, even when pregnant people are not included in initial vaccine clinical trials, once vaccine safety and immunogenicity are established in the general population, pregnant people should be included in vaccine studies as early as possible. In the meantime, it is important to remain transparent about the lack of information, acknowledge concerns, and to support those who decide to defer vaccination until more data are available. Notes No author has a potential conflict of interest or funding source. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Table Table 1. UK/US Advisory Body Recommendations on SARS-CoV-2 Vaccination of Pregnant and/or Lactating People Advisory Body Summary of Recommendations Link to Recommendations Public Health “As a matter of caution, COVID-19 vaccine is therefore https://www.gov.uk/government/pu England/ Medicines not routinely advised in pregnancy but there are some blications/safety-of-covid-19- and Healthcare circumstances in which the potential benefits of vaccines-when-given-in- products Regulatory vaccination are particularly important for pregnant pregnancy/the-safety-of-covid-19- Agency (MHRA) women” vaccines-when-given-in-pregnancy Royal College of “Trials testing the vaccine in pregnant and breastfeeding https://www.rcog.org.uk/globalasset Obstetricians and women have not yet taken place. Whether to get the s/documents/guidelines/2021-02-24- Gynaecologists vaccine in pregnancy is your choice.” combined-info-sheet-and-decision- (RCOG) aid.pdf Centers for Disease “Getting vaccinated is a personal choice. Any of the https://www.cdc.gov/coronavirus/20 Control and currently authorized COVID-19 vaccines can be offered 19- Prevention (CDC) to people who are pregnant or breastfeeding.” ncov/vaccines/recommendations/pre gnancy.html American College of “COVID-19 vaccines should not be withheld from https://www.acog.org/clinical/clinic Obstetricians and pregnant individuals…COVID-19 vaccines should be al-guidance/practice- Gynecologists offered to lactating individuals similar to non-lactating advisory/articles/2020/12/vaccinatin (ACOG) individuals.” g-pregnant-and-lactating-patients- against-covid-19 Society for Maternal- “SMFM strongly recommends that pregnant and lactating https://s3.amazonaws.com/cdn.smf Fetal Medicine people have access to the COVID-19 vaccines and that m.org/media/2838/Provider_Consid (SMFM) they engage in a discussion about potential benefits and erations_for_Engaging_in_COVID_ unknown risks with their healthcare providers regarding Vaccination_Considerations_3-3- receipt of the vaccine.” 21_(final).pdf American Society for “Patients undergoing fertility treatment and pregnant https://www.asrm.org/globalassets/a Reproductive patients should be encouraged to srm/asrm-content/news-and- Medicine (ASRM) receive vaccination based on eligibility criteria. Since the publications/covid- Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 vaccine is not a live virus, there is no reason to delay 19/covidtaskforceupdate13.pdf pregnancy attempts because of vaccination administration or to defer treatment until the second dose has been administered.” Academy of “The Academy of Breastfeeding Medicine does not https://www.bfmed.org/abm- Breastfeeding recommend cessation of breastfeeding for individuals statement-considerations-for-covid- Medicine (ABM) who are vaccinated against COVID-19. Individuals who 19-vaccination-in-lactation are lactating should discuss the risks and benefits of vaccination with their health care provider, within the context of their risk of contracting COVID-19 and of developing severe disease.” Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 References 1. Baden LR, El Sahly HM, Essink B, et al. Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med 2020. 2. Polack FP, Thomas SJ, Kitchin N, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med 2020; 383(27): 2603-15. 3. Voysey M, Clemens SAC, Madhi SA, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet 2020. 4. Stephenson KE, Le Gars M, Sadoff J, et al. Immunogenicity of the Ad26.COV2.S Vaccine for COVID-19. JAMA 2021. 5. Lokken EM, Huebner EM, Taylor GG, et al. Disease severity, pregnancy outcomes, and maternal deaths among pregnant patients with severe acute respiratory syndrome coronavirus 2 infection in Washington State. Am J Obstet Gynecol 2021. 6. Metz TD, Clifton RG, Hughes BL, et al. Disease Severity and Perinatal Outcomes of Pregnant Patients With Coronavirus Disease 2019 (COVID-19). Obstet Gynecol 7. Jering KS, Claggett BL, Cunningham JW, et al. Clinical Characteristics and Outcomes of Hospitalized Women Giving Birth With and Without COVID-19. JAMA Intern Med 2021. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 8. Pregnant women agonize over whether to get coronavirus vaccine. Available at: https://www.washingtonpost.com/health/pregnant-women-covid- vaccine/2021/01/01/b62ff88a-4492-11eb-b0e4-0f182923a025_story.html. Accessed January 02, 2020. 9. Sutton D, Fuchs K, D'Alton M, Goffman D. Universal Screening for SARS-CoV-2 in Women Admitted for Delivery. N Engl J Med 2020; 382(22): 2163-4. 10. Ahlberg M, Neovius M, Saltvedt S, et al. Association of SARS-CoV-2 Test Status and Pregnancy Outcomes. JAMA 2020. 11. Pineles BL, Alamo IC, Farooq N, et al. Racial-ethnic disparities and pregnancy outcomes in SARS-CoV-2 infection in a universally-tested cohort in Houston, Texas. Eur J Obstet Gynecol Reprod Biol 2020; 254: 329-30. 12. Allotey J, Stallings E, Bonet M, et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ 2020; 370: m3320. 13. Ellington S, Strid P, Tong VT, et al. Characteristics of Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status - United States, January 22-June 7, 2020. MMWR Morb Mortal Wkly Rep 2020; 69(25): 769- 14. Khalil A, Kalafat E, Benlioglu C, et al. SARS-CoV-2 infection in pregnancy: A systematic review and meta-analysis of clinical features and pregnancy outcomes. EClinicalMedicine 2020; 25: 100446. 15. Zambrano LD, Ellington S, Strid P, et al. Update: Characteristics of Symptomatic Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status - United States, January 22-October 3, 2020. MMWR Morb Mortal Wkly Rep 2020; 69(44): 1641-7. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 16. Martinez-Portilla RJ, Sotiriadis A, Chatzakis C, et al. Pregnant women with SARS- CoV-2 infection are at higher risk of death and severe pneumonia: propensity score- matched analysis of a nationwide prospective cohort study (COV19Mx). Ultrasound Obstet Gynecol 2020. 17. Khalil A, von Dadelszen P, Draycott T, Ugwumadu A, O'Brien P, Magee L. Change in the Incidence of Stillbirth and Preterm Delivery During the COVID-19 Pandemic. JAMA 2020. 18. Handley SC, Mullin AM, Elovitz MA, et al. Changes in Preterm Birth Phenotypes and Stillbirth at 2 Philadelphia Hospitals During the SARS-CoV-2 Pandemic, March- June 2020. JAMA 2020. 19. Stowe J, Smith H, Thurland K, Ramsay ME, Andrews N, Ladhani SN. Stillbirths During the COVID-19 Pandemic in England, April-June 2020. JAMA 2020. 20. Zhang H, Zhang H. Entry, egress and vertical transmission of SARS-CoV-2. J Mol Cell Biol 2021. 21. Vaccination Considerations for People who are Pregnant or Breastfeeding. Available at: https://www.cdc.gov/coronavirus/2019- ncov/vaccines/recommendations/pregnancy.html. Accessed December 24, 2020. 22. Kingsley JP, Vijay PK, Kumaresan J, Sathiakumar N. The Changing Aspects of Motherhood in Face of the COVID-19 Pandemic in Low- and Middle-Income Countries. Matern Child Health J 2020. 23. Nachega JB, Sam-Agudu NA, Budhram S, et al. Effect of SARS-CoV-2 Infection in Pregnancy on Maternal and Neonatal Outcomes in Africa: An AFREhealth Call for Evidence through Multicountry Research Collaboration. Am J Trop Med Hyg 2020. 24. Ethical Considerations for Including Women as Research Participants. Available at: https://www.acog.org/clinical/clinical-guidance/committee- Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 opinion/articles/2015/11/ethical-considerations-for-including-women-as-research- participants. Accessed December 29, 2020. 25. Global Advisory Committee on Vaccine Safety, 3-4 December 2003. Wkly Epidemiol Rec 2004; 79(3): 16-20. 26. Global vaccine safety: Meningococcal A conjugate vaccine during pregnancy. Available at: https://www.who.int/vaccine_safety/committee/topics/mena_conjugate/Jun_2014/en/. Accessed March 12. 27. Krubiner CB, Faden RR, Karron RA, et al. Pregnant women & vaccines against emerging epidemic threats: Ethics guidance for preparedness, research, and response. Vaccine 2021; 39(1): 85-120. 28. TASK FORCE ON RESEARCH SPECIFIC TO PREGNANT WOMEN AND LACTATING WOMEN: Report to Secretary, Health and Human Services Congress Available at: https://www.nichd.nih.gov/sites/default/files/2018- 09/PRGLAC_Report.pdf. Accessed March 19. 29. Malhotra A, Kumar A, Roehr CC, den Boer MC. Inclusion of children and pregnant women in COVID-19 intervention trials. Pediatr Res 2020. 30. Dashraath P, Nielsen-Saines K, Madhi SA, Baud D. COVID-19 vaccines and neglected pregnancy. Lancet 2020; 396(10252): e22. 31. Vaccines During and After Pregnancy. Available at: https://www.cdc.gov/vaccines/pregnancy/vacc-during-after.html. Accessed March 18. 32. Vaccines and Related Biological Products Advisory Committee Meeting December 10, 2020: FDA Briefing Document, Pfizer-BioNTech COVID-19 Vaccine. Available at: https://www.fda.gov/media/144245/download. Accessed December 24, 2020. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 33. Vaccines and Related Biological Products Advisory Committee Meeting December 17, 2020: FDA Briefing Document, Moderna COVID-19 Vaccine. Available at: https://www.fda.gov/media/144452/download. Accessed December 24, 2020. 34. Ramasamy MN, Minassian AM, Ewer KJ, et al. Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial. Lancet 2021; 396(10267): 1979-93. 35. Vaccines and Related Biological Products Advisory Committee Meeting February 26, 2021: FDA Briefing Document, Janssen Ad26.COV2.S Vaccine for the Prevention of COVID-19. Available at: https://www.fda.gov/media/146217/download. Accessed March 12. 36. Pardi N, Hogan MJ, Porter FW, Weissman D. mRNA vaccines - a new era in vaccinology. Nat Rev Drug Discov 2018; 17(4): 261-79. 37. Kremer EJ. Pros and Cons of Adenovirus-Based SARS-CoV-2 Vaccines. Mol Ther 2020; 28(11): 2303-4. 38. Knoll MD, Wonodi C. Oxford-AstraZeneca COVID-19 vaccine efficacy. Lancet 39. PFIZER AND BIONTECH COMMENCE GLOBAL CLINICAL TRIAL TO EVALUATE COVID-19 VACCINE IN PREGNANT WOMEN. Available at: https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech- commence-global-clinical-trial-evaluate. Accessed March 12. 40. Frequently Asked Questions: What is known about the safety of the vaccine for special populations (children, pregnant women, elderly people)? Available at: https://www.modernatx.com/covid19vaccine-eua/providers/faq#patient-vaccination. Accessed March 19. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 41. Rubin R. Pregnant People's Paradox-Excluded From Vaccine Trials Despite Having a Higher Risk of COVID-19 Complications. JAMA 2021; 325(11): 1027-8. 42. v-safe COVID-19 Vaccine Pregnancy Registry. Available at: https://www.cdc.gov/coronavirus/2019- ncov/vaccines/safety/vsafepregnancyregistry.html. Accessed March 12. 43. Shimabukuro T. COVID-19 vaccine safety update: Advisory Committee on Immunization Practices (ACIP), March 1, 2021. Available at: https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2021-02/28-03-01/05- covid- Shimabukuro.pdf?fbclid=IwAR3ceiw08RSTHGRaXgFEgQGnFawDPjR7tqVHoOlI2 EmVmj2vHF-YIFmOLJk. Accessed March 12. 44. COVID-19: The Green Book, Chapter 14a. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachme nt_data/file/961287/Greenbook_chapter_14a_v7_12Feb2021.pdf. Accessed March 45. Gray KB, Evan A. Bordt, Caroline Atyeo, Elizabeth Deriso, Babatunde Akinwunmi, Nicola Young, Aranxta Medina Baez, Lydia L. Shook, Dana Cvrk, Kaitlyn James, Rose M. De Guzman, Sara Brigida, Khady Diouf, Ilona Goldfarb, Lisa M. Bebell, Lael M. Yonker, Alessio Fasano, Sayed A. Rabi, Michal A. Elovitz, Galit Alter, Andrea G. Edlow. COVID-19 vaccine response in pregnant and lactating women: a cohort study. Available at: https://www.medrxiv.org/content/10.1101/2021.03.07.21253094v1. Accessed March Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 46. Sanche S, Lin YT, Xu C, Romero-Severson E, Hengartner N, Ke R. High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2. Emerg Infect Dis 2020; 26(7): 1470-7. 47. Rasmussen SA, Kelley CF, Horton JP, Jamieson DJ. Coronavirus Disease 2019 (COVID-19) Vaccines and Pregnancy: What Obstetricians Need to Know. Obstet Gynecol 2020; Publish Ahead of Print. 48. Craig AM, Hughes BL, Swamy GK. COVID-19 vaccines in pregnancy. American Journal of Obstetrics & Gynecology MFM 2021. 49. Refuerzo JS, Alexander JF, Leonard F, Leon M, Longo M, Godin B. Liposomes: a nanoscale drug carrying system to prevent indomethacin passage to the fetus in a pregnant mouse model. Am J Obstet Gynecol 2015; 212(4): 508 e1-7. 50. Golan Y, Prahl M, Cassidy A, et al. COVID-19 mRNA vaccine is not detected in human milk. medRxiv 2021: 2021.03.05.21252998. 51. Rottenstreich A, Gila Zarbiv, Esther Oiknine-Djian, Roy Zigron, Dana G. Wolf, Porat S. Efficient maternofetal transplacental transfer of anti- SARS-CoV-2 spike antibodies after antenatal SARS-CoV-2 BNT162b2 mRNA vaccination. Accessed March 19. 52. Golan Y, Mary Prahl, Arianna Cassidy, et al. Immune response during lactation after anti-SARS-CoV2 mRNA vaccine. Available at: https://www.medrxiv.org/content/10.1101/2021.03.09.21253241v2. 53. The safety of COVID-19 vaccines when given in pregnancy. Available at: https://www.gov.uk/government/publications/safety-of-covid-19-vaccines-when- given-in-pregnancy/the-safety-of-covid-19-vaccines-when-given-in-pregnancy. Accessed December 24, 2020. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 54. Updated advice on COVID-19 vaccination in pregnancy and women who are breastfeeding. Available at: https://www.rcog.org.uk/en/news/updated-advice-on- covid-19-vaccination-in-pregnancy-and-women-who-are-breastfeeding. Accessed December 30, 2020. 55. Evidence Table for COVID-19 Vaccines Allocation in Phases 1b and 1c of the Vaccination Program. Available at: https://www.cdc.gov/vaccines/hcp/acip-recs/vacc- specific/covid-19/evidence-table-phase-1b-1c.html. Accessed December 24, 2020. 56. Joint Statement Supporting Public Health Measures to Combat COVID-19. Available at: https://www.asrm.org/globalassets/asrm/asrm-content/news-and- publications/covid-19/joint-statement-on-covid19-health-measures.pdf. Accessed December 29, 2020. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Open Forum Infectious Diseases Oxford University Press

SARS-CoV-2 Vaccination During Pregnancy: A Complex Decision

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Copyright © 2021 Infectious Diseases Society of America
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Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 1 2 3 3,4,* Elizabeth Wenqian Wang, Jacqueline G. Parchem, Robert L. Atmar , Eva Clark Department of Infectious Diseases, University of Maryland St. Joseph Medical Center, Towson, MD, USA Department of Obstetrics, Gynecology and Reproductive Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, TX, USA Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA Department of Medicine, Section of Health Services Research, Center for Innovations in Quality, Safety, and Effectiveness (IQuESt), Michael E. DeBakey VA Medical Center and Baylor College of Medicine, Houston, TX, USA *Corresponding author: Eva Clark, eva.clark@bcm.edu, (713) 440-4400 (phone), (713) 748-7359 (fax), Houston HSR&D Center for Innovations in Quality, Effectiveness, and Safety (IQuESt) Baylor College of Medicine Michael E. DeBakey VA Medical Center, 2450 Holcombe Blvd., Suite 01Y, Houston, TX 77021, USA Conflict of Interest Statement: No authors report any conflicts of interest. Patient Consent Statement: None needed as no individual patients are mentioned in this article. Published by Oxford University Press on behalf of Infectious Diseases Society of America 2021. This work is written by (a) US Government employee(s) and is in the public domain in the US. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Abstract:As the first Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines passed United Kingdom and United States regulatory milestones in late 2020 and early 2021, multiple professional societies offered recommendations to assist pregnant and breastfeeding people as they choose whether to undergo vaccination. Despite such guidance, the lack of data describing vaccine safety, immunogenicity, and efficacy in pregnant and breastfeeding people has made this decision challenging for many. However, even considering the paucity of data, the known risks of Coronavirus Disease 2019 (COVID-19) during pregnancy likely outweigh the not yet fully elucidated risks of SARS-CoV-2 vaccines, which have reassuring safety and efficacy profiles among non-pregnant people. Keywords: SARS-CoV-2, COVID-19, vaccine, pregnancy, breastfeeding Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Essential workers and high-risk individuals in the United Kingdom and the United States began receiving doses of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines en masse as the first vaccine candidates obtained emergency use authorization in December 2020. While the safety, immunogenicity, and efficacy data for the four authorized vaccines are reassuring so far [1- 4], none of these vaccines has been systematically studied in pregnant and breastfeeding people, despite evidence that pregnancy may increase the risk of developing severe Coronavirus Disease 2019 (COVID-19) and related complications. In the United States, approximately 10% of pregnant people with COVID-19 have severe or critical illness [5, 6], and their in-hospital mortality is significantly higher compared to non-pregnant people of similar age [7]. The decision of whether to undergo SARS-CoV-2 vaccination during pregnancy is complex and causes apprehension among those considering vaccination [8]. Here, we discuss the risks and benefits of SARS-CoV-2 vaccination in pregnancy that may influence the decision-making process. Risk of pregnancy complications due to SARS-CoV-2 infection It is unclear whether pregnant people are more susceptible to SARS-CoV-2 infection than non- pregnant people. Many pregnant people infected with SARS-CoV-2 are asymptomatic (ranging from 44 to 86% in cohort studies with universally tested pregnant populations [9-11]). While the risk of mortality is low and comparable to that of the nonpregnant population (0.1-0.2%), preexisting comorbidities, higher maternal age, and higher body mass index are risk factors for severe COVID-19 in pregnancy [12-15]. Pregnant people who develop COVID-19 are more likely to require intensive care and have severe cardiopulmonary complications than their nonpregnant counterparts [13, 15, 16] (though these studies had several limitations; for instance, in the US Centers for Disease and Prevention [CDC] reports, pregnancy status and information on symptoms and underlying conditions were missing from more than 50% of cases [13, 15]). One retrospective evaluation of a large US cohort of hospitalized pregnant patients found that in-hospital mortality was significantly higher in those with COVID-19 compared to those without COVID-19 (141 [95% CI, 65-268] versus 5.0 [95% Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 CI, 3.1-7.7] deaths per 100,000 women) [7]. Additionally, some studies have suggested that pregnant people with COVID-19 have an increased risk of delivering premature and/or low birthweight infants, post-partum hemorrhage, and complications requiring caesarean delivery [10, 11, 17-19]. Vertical transmission of SARS-CoV-2 certainly occurs (both in utero, which is uncommon, and peripartum), though infected infants tend to have asymptomatic disease or only mild symptoms [20, 21]. Furthermore, pregnant people who develop COVID-19 in low resource settings – where pregnancy outcomes are already poorer due to prevalent comorbidities, coinfections, and socioeconomic and health system inequalities – often lack access to effective medications and high levels of supportive care [22, 23]. Exclusion of pregnant people from SARS-CoV-2 vaccine trials has resulted in limited data describing vaccine safety and efficacy in pregnancy Exclusion of pregnant people from vaccine trials has been an longstanding problem [24]. Their exclusion has resulted in vaccine recommendations for pregnant women based on little data (e.g., as for the initial recommendations for inactivated influenza vaccines [25], though subsequently robust clinical trials supported these recommendations) or recommendations only being given once “enough” pregnant people have been inadvertently vaccinated (e.g., as for MenAfriVac, a meningococcal A conjugate vaccine [26]). Since 2018, both governmental and independent advisory groups have published recommendations advocating for the early inclusion of pregnant people in the development and deployment of vaccines against emerging pathogens [27, 28]. Subsequently, during the rapid emergence of SARS-CoV-2, many authorities advocated for inclusion of pregnant people in SARS- CoV-2 vaccine trials [29, 30]. Despite this expert guidance and the potentially devastating consequences of SARS-CoV-2 infection, pregnant people were explicitly excluded from SARS-CoV- 2 vaccine clinical trials. Consequently, to date there are little published data describing the safety or efficacy of any SARS-CoV-2 vaccine in human pregnancy. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 SARS-CoV-2 vaccine platforms authorized in the UK and US and their potential risks Historically, protein-based vaccines (which are non-replicating) have been considered safe in pregnancy, for both mother and fetus. In fact, the CDC’s Advisory Committee on Immunization Practices (ACIP) recommends routine influenza and Tdap vaccination of all pregnant women as these vaccines are safe and induce maternal antibodies that are passed to the child in utero and via breastfeeding, thereby protecting the child from the diseases targeted by these vaccines [31]. As of March 15, 2021, four SARS-CoV-2 vaccines have gained regulatory authorization either in the UK or the US, including the Pfizer/BioNTech, Moderna/NIH, Oxford/AstraZeneca, and Janssen vaccines. While all four authorized SARS-CoV-2 vaccines are non-replicating vaccines, they are based on relatively new vaccine technology. Both the Pfizer/BioNTech and Moderna/NIH vaccines are messenger RNA (mRNA) nanoparticle-based platforms encoding the SARS-CoV-2 spike protein that require two doses spaced three to four weeks apart [32, 33]. The Oxford/AstraZeneca and Janssen vaccines are replication-deficient adenovirus vector vaccines containing spike protein DNA [34, 35]. The Oxford/AstraZeneca vaccine also requires two doses, while the Janssen vaccine is authorized for use as a single dose vaccine. In contrast to conventional protein-based vaccines, these nucleic acid- based vaccines provide genetic blueprints that allow the recipient’s own cells to produce the target antigen. Theoretical concerns have been suggested regarding the potential for host genome insertion and mutagenesis of vaccine genetic material. However, these concerns are unsubstantiated by scientific evidence; the SARS-CoV-2 genetic material carried by these vaccines is not infectious, does not incorporate into the recipient’s genome, and levels of vaccine mRNA/DNA and associated protein decline over several days post-vaccination as they are degraded by normal host cellular processes [36, 37]. Research on nanoparticle and adenovirus-vectored vaccines has been ongoing for decades [36, 37]. Specifically, human adenovirus serotype 26 (Ad26, which is the Janssen vaccine vector) has been used as a vector for other vaccines deemed safe for the general public, including the Ad26.ZEBOV/MVA-BN-Filo Ebola vaccine that was approved in Europe in 2020, as well as investigational vaccines against Zika, filovirus, HIV, HPV, malaria, and respiratory syncytial virus. No adverse pregnancy outcomes have been reported for these vaccines. However, the current COVID- Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 19 pandemic era is the first time that these vaccine types are being widely distributed among the general population. Though pregnant individuals were excluded from initial clinical trials of the four vaccines authorized to date, these trials do provide information on adverse effects unrelated to pregnancy, which are important for pregnant people to consider prior to vaccination. In these trials, reports of serious adverse effects were rare (most notably, three cases of transverse myelitis were reported during the AstraZeneca/Oxford vaccine clinical trials but were thought unlikely to be related to the vaccine after independent safety committee review [38]). Short-lived, mild to moderate adverse reactions are common after vaccination with all four of the SARS-CoV-2 vaccines discussed here. For the mRNA vaccines, the most common adverse reactions were injection site reactions (84.1% for the Pfizer/BioNTech vaccine, 91.6% for the Moderna/NIH vaccine), fatigue (62.9%, 68.5%), headache (55.1%, 63.0%), muscle pain (38.3%, 59.6%), chills (31.9%, 43.4%), joint pain (23.6%, 44.8%), and fever (14.2%, 14.8%) [32, 33]. Local injection site reactions, fatigue, headache, fever, and muscle pains also were common for the Oxford/AstraZeneca [34] and Janssen vaccines (for which the most common adverse reactions were injection site pain [48.6%], headache [38.9%], fatigue [38.2%], and myalgia [33.2%] [35]). Whether such adverse effects are associated with any risks to the mother or fetus is unclear. Of the four vaccines discussed here, Pfizer/BioNTech, Moderna/NIH, and Janssen have completed pre- clinical developmental and reproductive toxicity (DART) studies; none found any adverse effects on animal reproduction or fetal development. Regarding human data, small numbers of pregnant people were inadvertently enrolled during vaccine clinical trials (23, including 12 in the vaccine arm, for the Pfizer/BioNTech vaccine [32]; 13, including six in the vaccine arm, for the Moderna/NIH vaccine [33]; and eight, including four in the vaccine arm, for the Janssen vaccine [35]). Oxford/AstraZeneca has not yet publicly disclosed information on whether pregnancies were reported during their clinical trials. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Ongoing and planned SARS-CoV-2 vaccine evaluations in pregnant populations Though the small numbers of pregnant people discussed above were inadvertently enrolled in the SARS-CoV-2 vaccine clinical trials, the information generated by their follow-up is unlikely to provide conclusive evidence regarding vaccine safety or efficacy. Because pregnancy poses unique safety concerns, it is essential that pregnant people are included in appropriately designed vaccine trials. Pfizer recently announced that they will perform a global Phase 2/3 trial to evaluate the safety, tolerability and immunogenicity of SARS-CoV-2 vaccine in pregnant people who are 18 years and older [39]. The trial is a randomized, placebo-controlled, observer-blind study of 4,000 healthy women vaccinated between 24 to 34 weeks of gestation. Each woman will participate in the study for seven to ten months, depending on whether randomized to receive vaccine or placebo, and their infants will be monitored to six months of age. Moderna has created a registry of pregnant vaccinees and is planning a prospective observational study to assess obstetric, neonatal, and infant outcomes [40]. Janssen is planning a phase 2 placebo-controlled trial in more than 800 pregnant people [41]. AstraZeneca’s plans for clinical trials in pregnant people are still uncertain. It is important that these trials move forward to evaluate the remaining unknown issues related to pregnancy such as vaccine safety and immunogenicity (including rates of antibody transfer to neonates). However, potential problems with this delayed approach to inclusion of pregnant people in vaccine clinical trials include (1) data are unavailable for pregnant people otherwise eligible for vaccination now, obligating reliance on observational data; (2) potential low trial enrollment if pregnant people do not want to risk being in the placebo arm; and (3) the resultant trial sample size may be too small to detect differences in perinatal outcomes. Additionally, the CDC has established a voluntary smartphone-based registry for SARS-CoV-2 vaccine recipients called “v-safe,” which includes both a post-vaccination “health checker” and a registry of pregnant people; as of March 15, 2021, more than 50,000 pregnant people were enrolled in Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 this monitoring program [42]. So far, v-safe data indicate no safety issues. Most adverse events (73%) reported were not related to pregnancy. Of the pregnancy-related adverse events, miscarriage was reported most frequently (in 29 participants); however, the reported miscarriage numbers reflect background rates [43]. The UK Medicines and Healthcare Products Regulatory Agency (MHRA) has a similar post-vaccination registry and has also found no safety concerns in pregnant people during their data analysis [44]. Public health and personal advantages of SARS-CoV-2 vaccination of pregnant and breastfeeding people The obvious advantage to SARS-CoV-2 vaccination is protection of pregnant people – and, to some extent, their neonates – from the potentially devastating complications of SARS-CoV-2 infection. In non-pregnant populations, the efficacies reported for the authorized SARS-CoV-2 vaccines are 95.0% for the Pfizer/BioNTech vaccine [32], 94.1% for the Moderna/NIH vaccine [33], 70.4% for the Oxford/AstraZeneca vaccine (notably, this percentage is derived from pooled analysis of groups that received different vaccine doses [38]), and 66.9% for the Janssen vaccine [35]. Efficacies are likely to be similarly robust in pregnant populations. Prospective studies have already described SARS-CoV-2 vaccine-induced immune responses in pregnant and lactating people, with even higher antibody titers than those induced by SARS-CoV-2 infection during pregnancy [45]. From a public health perspective, broad vaccine uptake (i.e., an estimated 55-82% of the population) is needed to achieve effective population immunity [46], which undoubtedly will take some time. Vaccinating as many people as possible, including pregnant and breastfeeding people, will help attain such levels more quickly. Finally, many essential workers, particularly those who are currently pregnant, have anxiety about acquiring SARS-CoV-2 infection and transmitting the virus to family, patients, and co-workers [8]; vaccination would likely ameliorate these anxieties and provide welcomed relief and peace of mind for many. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Impact of SARS-CoV-2 vaccination on fetuses and breastfeeding infants While mRNA nanoparticle and adenovirus vector SARS-CoV-2 vaccines are not thought to pose significant risk to the recipient’s fetus, important questions regarding fetal risk are only beginning to be answered [47, 48]. For instance, whether intact vaccine particles cross the placenta and enter fetal cells remains largely unknown, though studies of other lipid nanoparticle platforms suggest that they do not cross to the fetus [49]. The publication of pre-clinical DART study data and small human studies are helping to clarify such issues. For instance, one study evaluated six women after receipt of mRNA-based vaccines (five received Pfizer/BioNTech and one received Moderna/NIH) and found no evidence of vaccine mRNA in breast milk samples collected within two days of vaccination [50]. Regarding whether maternal SARS-CoV-2 immunization leads to transfer of specific antibodies to infants, one study of 20 mother-infant pairs demonstrated efficient transplacental transfer of anti- SARS-CoV-2 spike antibodies after antenatal vaccination with the Pfizer/BioNTech vaccine [51], and another showed presence of vaccine-derived IgA antibodies in breastmilk three to four weeks post- vaccination with the Pfizer/BioNTech (n=14) and Moderna (n=9) vaccines [52]. In the latter study, IgA antibody titers in breastmilk were similar to those of participants who had experienced natural SARS-CoV-2 infection. Such findings should encourage vaccination of breastfeeding people, among whom any theoretical risks related to vaccination are likely the same as those of the general population. Additionally, both Pfizer and Moderna are conducting clinical trials of their vaccines in children, and Janssen plans to start clinical trials in adolescents in March 2021, which will yield needed data on the safety, immunogenicity, and efficacy in these populations. Regulatory and professional body guidance on SARS-CoV-2 vaccination in pregnancy The paucity of data on SARS-CoV-2 vaccines in pregnant and breastfeeding populations makes counseling patients challenging. Many regulatory agencies in the UK and the US have made Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 recommendations regarding SARS-CoV-2 vaccination in pregnancy (Table 1). Advisory bodies in the UK, such as the MHRA and the Royal College of Obstetricians and Gynaecologists (RCOG) initially advised against offering SARS-CoV-2 vaccines to people who are pregnant and breastfeeding, due to lack of safety data in these populations [53], but updated their positions on December 30, 2020 [54], to recommend consideration of vaccination in those who are frontline personnel or those who have underlying conditions that make them high risk of being infected with or experiencing serious complications of COVID-19, which includes pregnancy [54]. In contrast, the CDC’s ACIP advises allowing all pregnant and breastfeeding people to choose whether to be vaccinated [21], and, in the CDC’s recommendations for prioritization of SARS-CoV-2 vaccine allocation, pregnancy is included as a “high risk” condition eligible for vaccination during Phase 1C [55]. Multiple reproductive medicine organizations, including the American College of Obstetricians and Gynecologists (ACOG), the Society for Maternal-Fetal Medicine (SMFM), the American Society for Reproductive Medicine (ASRM), and the Academy of Breastfeeding Medicine (ABM), agree that SARS-CoV-2 vaccines should not be withheld from pregnant and breastfeeding people who are otherwise eligible [56]. Clearly, with all the above data (and lack thereof) and factors to consider, the decision of whether to undergo SARS-CoV-2 vaccination during pregnancy or while breastfeeding is a complex one. Healthcare provider counselling of pregnant people should focus on the available vaccine safety and efficacy data in the context of the individual’s personal risk of SARS-CoV-2 exposure, underlying medical conditions, and SARS-CoV-2 prevalence in the community. Several of the advisory bodies mentioned have published guides for counselling pregnant and lactating people as they contemplate the pros and cons of vaccination (e.g., a “conversation guide” from ACOG can be found here: https://www.acog.org/- /media/project/acog/acogorg/files/pdfs/clinical-guidance/practice-advisory/covid19vaccine- conversationguide-121520-v2.pdf?la=en&hash=439FFEC1991B7DD3925352A5308C7C42, and SMFM provides “Provider Considerations for Engaging in COVID-19 Vaccine Counseling Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 With Pregnant and Lactating Patients” here: https://s3.amazonaws.com/cdn.smfm.org/media/2838/Provider_Considerations_for_Engaging_in_CO VID_Vaccination_Considerations_3-3-21_(final).pdf). Conclusions Because pregnant people were explicitly excluded from SARS-CoV-2 vaccine clinical trials, little data are available to guide them as they decide whether to undergo SARS-CoV-2 vaccination. Even so, given the reassuring safety and efficacy profiles of the SARS-CoV-2 vaccines that have gained UK/US regulatory authorization to date, the known risks of COVID-19 likely outweigh the unclear risks of SARS-CoV-2 vaccines for pregnant and breastfeeding people. Going forward, every effort should be made to collect data on the safety, immunogenicity, and efficacy of SARS-CoV-2 vaccines in pregnant and breastfeeding people through well-designed clinical trials that include these populations. As a matter of expediency, even when pregnant people are not included in initial vaccine clinical trials, once vaccine safety and immunogenicity are established in the general population, pregnant people should be included in vaccine studies as early as possible. In the meantime, it is important to remain transparent about the lack of information, acknowledge concerns, and to support those who decide to defer vaccination until more data are available. Notes No author has a potential conflict of interest or funding source. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 Table Table 1. UK/US Advisory Body Recommendations on SARS-CoV-2 Vaccination of Pregnant and/or Lactating People Advisory Body Summary of Recommendations Link to Recommendations Public Health “As a matter of caution, COVID-19 vaccine is therefore https://www.gov.uk/government/pu England/ Medicines not routinely advised in pregnancy but there are some blications/safety-of-covid-19- and Healthcare circumstances in which the potential benefits of vaccines-when-given-in- products Regulatory vaccination are particularly important for pregnant pregnancy/the-safety-of-covid-19- Agency (MHRA) women” vaccines-when-given-in-pregnancy Royal College of “Trials testing the vaccine in pregnant and breastfeeding https://www.rcog.org.uk/globalasset Obstetricians and women have not yet taken place. Whether to get the s/documents/guidelines/2021-02-24- Gynaecologists vaccine in pregnancy is your choice.” combined-info-sheet-and-decision- (RCOG) aid.pdf Centers for Disease “Getting vaccinated is a personal choice. Any of the https://www.cdc.gov/coronavirus/20 Control and currently authorized COVID-19 vaccines can be offered 19- Prevention (CDC) to people who are pregnant or breastfeeding.” ncov/vaccines/recommendations/pre gnancy.html American College of “COVID-19 vaccines should not be withheld from https://www.acog.org/clinical/clinic Obstetricians and pregnant individuals…COVID-19 vaccines should be al-guidance/practice- Gynecologists offered to lactating individuals similar to non-lactating advisory/articles/2020/12/vaccinatin (ACOG) individuals.” g-pregnant-and-lactating-patients- against-covid-19 Society for Maternal- “SMFM strongly recommends that pregnant and lactating https://s3.amazonaws.com/cdn.smf Fetal Medicine people have access to the COVID-19 vaccines and that m.org/media/2838/Provider_Consid (SMFM) they engage in a discussion about potential benefits and erations_for_Engaging_in_COVID_ unknown risks with their healthcare providers regarding Vaccination_Considerations_3-3- receipt of the vaccine.” 21_(final).pdf American Society for “Patients undergoing fertility treatment and pregnant https://www.asrm.org/globalassets/a Reproductive patients should be encouraged to srm/asrm-content/news-and- Medicine (ASRM) receive vaccination based on eligibility criteria. Since the publications/covid- Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 vaccine is not a live virus, there is no reason to delay 19/covidtaskforceupdate13.pdf pregnancy attempts because of vaccination administration or to defer treatment until the second dose has been administered.” Academy of “The Academy of Breastfeeding Medicine does not https://www.bfmed.org/abm- Breastfeeding recommend cessation of breastfeeding for individuals statement-considerations-for-covid- Medicine (ABM) who are vaccinated against COVID-19. Individuals who 19-vaccination-in-lactation are lactating should discuss the risks and benefits of vaccination with their health care provider, within the context of their risk of contracting COVID-19 and of developing severe disease.” Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 References 1. Baden LR, El Sahly HM, Essink B, et al. Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med 2020. 2. Polack FP, Thomas SJ, Kitchin N, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med 2020; 383(27): 2603-15. 3. Voysey M, Clemens SAC, Madhi SA, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet 2020. 4. Stephenson KE, Le Gars M, Sadoff J, et al. Immunogenicity of the Ad26.COV2.S Vaccine for COVID-19. JAMA 2021. 5. Lokken EM, Huebner EM, Taylor GG, et al. Disease severity, pregnancy outcomes, and maternal deaths among pregnant patients with severe acute respiratory syndrome coronavirus 2 infection in Washington State. Am J Obstet Gynecol 2021. 6. Metz TD, Clifton RG, Hughes BL, et al. Disease Severity and Perinatal Outcomes of Pregnant Patients With Coronavirus Disease 2019 (COVID-19). Obstet Gynecol 7. Jering KS, Claggett BL, Cunningham JW, et al. Clinical Characteristics and Outcomes of Hospitalized Women Giving Birth With and Without COVID-19. JAMA Intern Med 2021. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 8. Pregnant women agonize over whether to get coronavirus vaccine. Available at: https://www.washingtonpost.com/health/pregnant-women-covid- vaccine/2021/01/01/b62ff88a-4492-11eb-b0e4-0f182923a025_story.html. Accessed January 02, 2020. 9. Sutton D, Fuchs K, D'Alton M, Goffman D. Universal Screening for SARS-CoV-2 in Women Admitted for Delivery. N Engl J Med 2020; 382(22): 2163-4. 10. Ahlberg M, Neovius M, Saltvedt S, et al. Association of SARS-CoV-2 Test Status and Pregnancy Outcomes. JAMA 2020. 11. Pineles BL, Alamo IC, Farooq N, et al. Racial-ethnic disparities and pregnancy outcomes in SARS-CoV-2 infection in a universally-tested cohort in Houston, Texas. Eur J Obstet Gynecol Reprod Biol 2020; 254: 329-30. 12. Allotey J, Stallings E, Bonet M, et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ 2020; 370: m3320. 13. Ellington S, Strid P, Tong VT, et al. Characteristics of Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status - United States, January 22-June 7, 2020. MMWR Morb Mortal Wkly Rep 2020; 69(25): 769- 14. Khalil A, Kalafat E, Benlioglu C, et al. SARS-CoV-2 infection in pregnancy: A systematic review and meta-analysis of clinical features and pregnancy outcomes. EClinicalMedicine 2020; 25: 100446. 15. Zambrano LD, Ellington S, Strid P, et al. Update: Characteristics of Symptomatic Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status - United States, January 22-October 3, 2020. MMWR Morb Mortal Wkly Rep 2020; 69(44): 1641-7. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 16. Martinez-Portilla RJ, Sotiriadis A, Chatzakis C, et al. Pregnant women with SARS- CoV-2 infection are at higher risk of death and severe pneumonia: propensity score- matched analysis of a nationwide prospective cohort study (COV19Mx). Ultrasound Obstet Gynecol 2020. 17. Khalil A, von Dadelszen P, Draycott T, Ugwumadu A, O'Brien P, Magee L. Change in the Incidence of Stillbirth and Preterm Delivery During the COVID-19 Pandemic. JAMA 2020. 18. Handley SC, Mullin AM, Elovitz MA, et al. Changes in Preterm Birth Phenotypes and Stillbirth at 2 Philadelphia Hospitals During the SARS-CoV-2 Pandemic, March- June 2020. JAMA 2020. 19. Stowe J, Smith H, Thurland K, Ramsay ME, Andrews N, Ladhani SN. Stillbirths During the COVID-19 Pandemic in England, April-June 2020. JAMA 2020. 20. Zhang H, Zhang H. Entry, egress and vertical transmission of SARS-CoV-2. J Mol Cell Biol 2021. 21. Vaccination Considerations for People who are Pregnant or Breastfeeding. Available at: https://www.cdc.gov/coronavirus/2019- ncov/vaccines/recommendations/pregnancy.html. Accessed December 24, 2020. 22. Kingsley JP, Vijay PK, Kumaresan J, Sathiakumar N. The Changing Aspects of Motherhood in Face of the COVID-19 Pandemic in Low- and Middle-Income Countries. Matern Child Health J 2020. 23. Nachega JB, Sam-Agudu NA, Budhram S, et al. Effect of SARS-CoV-2 Infection in Pregnancy on Maternal and Neonatal Outcomes in Africa: An AFREhealth Call for Evidence through Multicountry Research Collaboration. Am J Trop Med Hyg 2020. 24. Ethical Considerations for Including Women as Research Participants. Available at: https://www.acog.org/clinical/clinical-guidance/committee- Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 opinion/articles/2015/11/ethical-considerations-for-including-women-as-research- participants. Accessed December 29, 2020. 25. Global Advisory Committee on Vaccine Safety, 3-4 December 2003. Wkly Epidemiol Rec 2004; 79(3): 16-20. 26. Global vaccine safety: Meningococcal A conjugate vaccine during pregnancy. Available at: https://www.who.int/vaccine_safety/committee/topics/mena_conjugate/Jun_2014/en/. Accessed March 12. 27. Krubiner CB, Faden RR, Karron RA, et al. Pregnant women & vaccines against emerging epidemic threats: Ethics guidance for preparedness, research, and response. Vaccine 2021; 39(1): 85-120. 28. TASK FORCE ON RESEARCH SPECIFIC TO PREGNANT WOMEN AND LACTATING WOMEN: Report to Secretary, Health and Human Services Congress Available at: https://www.nichd.nih.gov/sites/default/files/2018- 09/PRGLAC_Report.pdf. Accessed March 19. 29. Malhotra A, Kumar A, Roehr CC, den Boer MC. Inclusion of children and pregnant women in COVID-19 intervention trials. Pediatr Res 2020. 30. Dashraath P, Nielsen-Saines K, Madhi SA, Baud D. COVID-19 vaccines and neglected pregnancy. Lancet 2020; 396(10252): e22. 31. Vaccines During and After Pregnancy. Available at: https://www.cdc.gov/vaccines/pregnancy/vacc-during-after.html. Accessed March 18. 32. Vaccines and Related Biological Products Advisory Committee Meeting December 10, 2020: FDA Briefing Document, Pfizer-BioNTech COVID-19 Vaccine. Available at: https://www.fda.gov/media/144245/download. Accessed December 24, 2020. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 33. Vaccines and Related Biological Products Advisory Committee Meeting December 17, 2020: FDA Briefing Document, Moderna COVID-19 Vaccine. Available at: https://www.fda.gov/media/144452/download. Accessed December 24, 2020. 34. Ramasamy MN, Minassian AM, Ewer KJ, et al. Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial. Lancet 2021; 396(10267): 1979-93. 35. Vaccines and Related Biological Products Advisory Committee Meeting February 26, 2021: FDA Briefing Document, Janssen Ad26.COV2.S Vaccine for the Prevention of COVID-19. Available at: https://www.fda.gov/media/146217/download. Accessed March 12. 36. Pardi N, Hogan MJ, Porter FW, Weissman D. mRNA vaccines - a new era in vaccinology. Nat Rev Drug Discov 2018; 17(4): 261-79. 37. Kremer EJ. Pros and Cons of Adenovirus-Based SARS-CoV-2 Vaccines. Mol Ther 2020; 28(11): 2303-4. 38. Knoll MD, Wonodi C. Oxford-AstraZeneca COVID-19 vaccine efficacy. Lancet 39. PFIZER AND BIONTECH COMMENCE GLOBAL CLINICAL TRIAL TO EVALUATE COVID-19 VACCINE IN PREGNANT WOMEN. Available at: https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech- commence-global-clinical-trial-evaluate. Accessed March 12. 40. Frequently Asked Questions: What is known about the safety of the vaccine for special populations (children, pregnant women, elderly people)? Available at: https://www.modernatx.com/covid19vaccine-eua/providers/faq#patient-vaccination. Accessed March 19. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 41. Rubin R. Pregnant People's Paradox-Excluded From Vaccine Trials Despite Having a Higher Risk of COVID-19 Complications. JAMA 2021; 325(11): 1027-8. 42. v-safe COVID-19 Vaccine Pregnancy Registry. Available at: https://www.cdc.gov/coronavirus/2019- ncov/vaccines/safety/vsafepregnancyregistry.html. Accessed March 12. 43. Shimabukuro T. COVID-19 vaccine safety update: Advisory Committee on Immunization Practices (ACIP), March 1, 2021. Available at: https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2021-02/28-03-01/05- covid- Shimabukuro.pdf?fbclid=IwAR3ceiw08RSTHGRaXgFEgQGnFawDPjR7tqVHoOlI2 EmVmj2vHF-YIFmOLJk. Accessed March 12. 44. COVID-19: The Green Book, Chapter 14a. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachme nt_data/file/961287/Greenbook_chapter_14a_v7_12Feb2021.pdf. Accessed March 45. Gray KB, Evan A. Bordt, Caroline Atyeo, Elizabeth Deriso, Babatunde Akinwunmi, Nicola Young, Aranxta Medina Baez, Lydia L. Shook, Dana Cvrk, Kaitlyn James, Rose M. De Guzman, Sara Brigida, Khady Diouf, Ilona Goldfarb, Lisa M. Bebell, Lael M. Yonker, Alessio Fasano, Sayed A. Rabi, Michal A. Elovitz, Galit Alter, Andrea G. Edlow. COVID-19 vaccine response in pregnant and lactating women: a cohort study. Available at: https://www.medrxiv.org/content/10.1101/2021.03.07.21253094v1. Accessed March Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 46. Sanche S, Lin YT, Xu C, Romero-Severson E, Hengartner N, Ke R. High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2. Emerg Infect Dis 2020; 26(7): 1470-7. 47. Rasmussen SA, Kelley CF, Horton JP, Jamieson DJ. Coronavirus Disease 2019 (COVID-19) Vaccines and Pregnancy: What Obstetricians Need to Know. Obstet Gynecol 2020; Publish Ahead of Print. 48. Craig AM, Hughes BL, Swamy GK. COVID-19 vaccines in pregnancy. American Journal of Obstetrics & Gynecology MFM 2021. 49. Refuerzo JS, Alexander JF, Leonard F, Leon M, Longo M, Godin B. Liposomes: a nanoscale drug carrying system to prevent indomethacin passage to the fetus in a pregnant mouse model. Am J Obstet Gynecol 2015; 212(4): 508 e1-7. 50. Golan Y, Prahl M, Cassidy A, et al. COVID-19 mRNA vaccine is not detected in human milk. medRxiv 2021: 2021.03.05.21252998. 51. Rottenstreich A, Gila Zarbiv, Esther Oiknine-Djian, Roy Zigron, Dana G. Wolf, Porat S. Efficient maternofetal transplacental transfer of anti- SARS-CoV-2 spike antibodies after antenatal SARS-CoV-2 BNT162b2 mRNA vaccination. Accessed March 19. 52. Golan Y, Mary Prahl, Arianna Cassidy, et al. Immune response during lactation after anti-SARS-CoV2 mRNA vaccine. Available at: https://www.medrxiv.org/content/10.1101/2021.03.09.21253241v2. 53. The safety of COVID-19 vaccines when given in pregnancy. Available at: https://www.gov.uk/government/publications/safety-of-covid-19-vaccines-when- given-in-pregnancy/the-safety-of-covid-19-vaccines-when-given-in-pregnancy. Accessed December 24, 2020. Downloaded from https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofab180/6220034 by DeepDyve user on 18 May 2021 54. Updated advice on COVID-19 vaccination in pregnancy and women who are breastfeeding. Available at: https://www.rcog.org.uk/en/news/updated-advice-on- covid-19-vaccination-in-pregnancy-and-women-who-are-breastfeeding. Accessed December 30, 2020. 55. Evidence Table for COVID-19 Vaccines Allocation in Phases 1b and 1c of the Vaccination Program. Available at: https://www.cdc.gov/vaccines/hcp/acip-recs/vacc- specific/covid-19/evidence-table-phase-1b-1c.html. Accessed December 24, 2020. 56. Joint Statement Supporting Public Health Measures to Combat COVID-19. Available at: https://www.asrm.org/globalassets/asrm/asrm-content/news-and- publications/covid-19/joint-statement-on-covid19-health-measures.pdf. Accessed December 29, 2020.

Journal

Open Forum Infectious DiseasesOxford University Press

Published: Apr 10, 2021

Keywords: breast feeding; pregnancy; sars-cov-2; covid-19 vaccines; vaccine exposure during pregnancy; covid-19; vaccine safety; immunogenicity; coronavirus; safety; vaccination; vaccines; severe acute respiratory syndrome

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