BNT162b2 Vaccination and SARS-CoV-2 Infection in Pregnant Women | Pregnancy | JN Learning | AMA Ed Hub [Skip to Content]
[Skip to Content Landing]

Association Between BNT162b2 Vaccination and Incidence of SARS-CoV-2 Infection in Pregnant Women

Educational Objective
To identify the key insights or developments described in this article
1 Credit CME
Key Points

Question  Among pregnant women, what is the association between receipt of BNT162b2 messenger RNA vaccine and risk of SARS-CoV-2 infection?

Findings  In a retrospective cohort study that included 15 060 pregnant women in Israel, vaccination with BNT162b2 vs nonvaccination was associated with an adjusted hazard ratio for incident SARS-CoV-2 infection of 0.22; this was statistically significant.

Meaning  Among pregnant women, receipt of the BNT162b2 vaccine was associated with a lower risk of incident SARS-CoV-2 infection.


Importance  Data on BNT162b2 messenger RNA (mRNA) vaccine (Pfizer-BioNTech) effectiveness and safety in pregnancy are currently lacking because pregnant women were excluded from the phase 3 trial.

Objective  To assess the association between receipt of BNT162b2 mRNA vaccine and risk of SARS-CoV-2 infection among pregnant women.

Design, Setting, and Participants  This was a retrospective cohort study within the pregnancy registry of a large state-mandated health care organization in Israel. Pregnant women vaccinated with a first dose from December 19, 2020, through February 28, 2021, were 1:1 matched to unvaccinated women by age, gestational age, residential area, population subgroup, parity, and influenza immunization status. Follow-up ended on April 11, 2021.

Exposures  Exposure was defined by receipt of the BNT162b2 mRNA vaccine. To maintain comparability, nonexposed women who were subsequently vaccinated were censored 10 days after their exposure, along with their matched pair.

Main Outcomes and Measures  The primary outcome was polymerase chain reaction–validated SARS-CoV-2 infection at 28 days or more after the first vaccine dose.

Results  The cohort included 7530 vaccinated and 7530 matched unvaccinated women, 46% and 33% in the second and third trimester, respectively, with a mean age of 31.1 years (SD, 4.9 years). The median follow-up for the primary outcome was 37 days (interquartile range, 21-54 days; range, 0-70). There were 118 SARS-CoV-2 infections in the vaccinated group and 202 in the unvaccinated group. Among infected women, 88 of 105 (83.8%) were symptomatic in the vaccinated group vs 149 of 179 (83.2%) in the unvaccinated group (P ≥ .99). During 28 to 70 days of follow-up, there were 10 infections in the vaccinated group and 46 in the unvaccinated group. The hazards of infection were 0.33% vs 1.64% in the vaccinated and unvaccinated groups, respectively, representing an absolute difference of 1.31% (95% CI, 0.89%-1.74%), with an adjusted hazard ratio of 0.22 (95% CI, 0.11-0.43). Vaccine-related adverse events were reported by 68 patients; none was severe. The most commonly reported symptoms were headache (n = 10, 0.1%), general weakness (n = 8, 0.1%), nonspecified pain (n = 6, <0.1%), and stomachache (n = 5, <0.1%).

Conclusions and Relevance  In this retrospective cohort study of pregnant women, BNT162b2 mRNA vaccination compared with no vaccination was associated with a significantly lower risk of SARS-CoV-2 infection. Interpretation of study findings is limited by the observational design.

Sign in to take quiz and track your certificates

Buy This Activity

JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 CME Credit™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC

CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.

Article Information

Corresponding Author: Inbal Goldshtein, PhD, Maccabi Healthcare Services, 4 Yehezkel Kaufmann St, Tel Aviv, Israel 68125 (

Accepted for Publication: June 21, 2021.

Published Online: July 12, 2021. doi:10.1001/jama.2021.11035

Author Contributions: Dr Goldshtein had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Goldshtein, Rotem, Gorfine, Chodick, Segal.

Acquisition, analysis, or interpretation of data: Goldshtein, Nevo, Steinberg, Gorfine, Segal.

Drafting of the manuscript: Goldshtein, Steinberg, Segal.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Goldshtein, Nevo, Steinberg, Gorfine.

Administrative, technical, or material support: Goldshtein.

Supervision: Goldshtein, Gorfine, Segal.

Conflict of Interest Disclosures: None reported.

Additional Contributions: We thank Iris Goren, MD, Vered Mourad, DVM, Rivka Maroko, BSC, and Hillel Alapi, BA, from Maccabi Healthcare Services for their contribution to the establishment and maintenance of computerized pregnancy and COVID-19 registries. Their assistance was provided as part of their work in the health fund. No one received any additional compensation beyond usual salary for his or her contributions.

Alberca  RW , Pereira  NZ , Oliveira  LMDS , Gozzi-Silva  SC , Sato  MN .  Pregnancy, viral infection, and COVID-19.   Front Immunol. 2020;11:1672. doi:10.3389/fimmu.2020.01672PubMedGoogle ScholarCrossref
Crovetto  F , Crispi  F , Llurba  E , Figueras  F , Gómez-Roig  MD , Gratacós  E .  Seroprevalence and presentation of SARS-CoV-2 in pregnancy.   Lancet. 2020;396(10250):530-531. doi:10.1016/S0140-6736(20)31714-1PubMedGoogle ScholarCrossref
Allotey  J , Stallings  E , Bonet  M ,  et al; PregCOV-19 Living Systematic Review Consortium.  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. doi:10.1136/bmj.m3320PubMedGoogle Scholar
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):769-775. doi:10.15585/mmwr.mm6925a1PubMedGoogle ScholarCrossref
Collin  J , Byström  E , Carnahan  A , Ahrne  M .  Public Health Agency of Sweden’s brief report: pregnant and postpartum women with severe acute respiratory syndrome coronavirus 2 infection in intensive care in Sweden.   Acta Obstet Gynecol Scand. 2020;99(7):819-822. doi:10.1111/aogs.13901PubMedGoogle ScholarCrossref
Pierce-Williams  RAM , Burd  J , Felder  L ,  et al.  Clinical course of severe and critical coronavirus disease 2019 in hospitalized pregnancies: a United States cohort study.   Am J Obstet Gynecol MFM. 2020;2(3):100134. doi:10.1016/j.ajogmf.2020.100134PubMedGoogle Scholar
Savasi  VM , Parisi  F , Patanè  L ,  et al.  Clinical findings and disease severity in hospitalized pregnant women with coronavirus disease 2019 (COVID-19).   Obstet Gynecol. 2020;136(2):252-258. doi:10.1097/AOG.0000000000003979PubMedGoogle ScholarCrossref
Knight  M , Bunch  K , Vousden  N ,  et al; UK Obstetric Surveillance System SARS-CoV-2 Infection in Pregnancy Collaborative Group.  Characteristics and outcomes of pregnant women admitted to hospital with confirmed SARS-CoV-2 infection in UK: national population based cohort study.   BMJ. 2020;369:m2107. doi:10.1136/bmj.m2107PubMedGoogle Scholar
Liang  H , Acharya  G .  Novel corona virus disease (COVID-19) in pregnancy: what clinical recommendations to follow?   Acta Obstet Gynecol Scand. 2020;99(4):439-442. doi:10.1111/aogs.13836PubMedGoogle ScholarCrossref
Polack  FP , Thomas  SJ , Kitchin  N ,  et al; C4591001 Clinical Trial Group.  Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine.   N Engl J Med. 2020;383(27):2603-2615. doi:10.1056/NEJMoa2034577PubMedGoogle ScholarCrossref
Chodick  G , Tene  L , Patalon  T ,  et al.  Assessment of effectiveness of 1 dose of BNT162b2 vaccine for SARS-CoV-2 infection 13 to 24 days after immunization.   JAMA Netw Open. 2021;4(6):e2115985-e2115985. doi:10.1001/jamanetworkopen.2021.15985PubMedGoogle ScholarCrossref
Rossman  H , Shilo  S , Meir  T , Gorfine  M , Shalit  U , Segal  E .  COVID-19 dynamics after a national immunization program in Israel.   Nat Med. 2021;27(6):1055-1061. doi:10.1038/s41591-021-01337-2PubMedGoogle ScholarCrossref
GlobeNewswire. Pfizer and BioNTech commence global clinical trial to evaluate COVID-19 vaccine in pregnant women. Accessed February 19, 2021.
Israeli Ministry of Health. Vaccination recommendation for high-risk pregnant women. Article in Hebrew. Accessed February 19, 2021.
National Insurance Institute of Israel. Capitation tables. Article in Hebrew. Accessed March 1, 2021.
Dagan  N , Barda  N , Kepten  E ,  et al.  BNT162b2 mRNA Covid-19 vaccine in a nationwide mass vaccination setting.   N Engl J Med. 2021;384(15):1412-1423. doi:10.1056/NEJMoa2101765PubMedGoogle ScholarCrossref
Chodick  G , Heymann  AD , Shalev  V , Kookia  E .  The epidemiology of diabetes in a large Israeli HMO.   Eur J Epidemiol. 2003;18(12):1143-1146. doi:10.1023/B:EJEP.0000006635.36802.c8PubMedGoogle ScholarCrossref
Shalev  V , Chodick  G , Goren  I , Silber  H , Kokia  E , Heymann  AD .  The use of an automated patient registry to manage and monitor cardiovascular conditions and related outcomes in a large health organization.   Int J Cardiol. 2011;152(3):345-349. doi:10.1016/j.ijcard.2010.08.002PubMedGoogle ScholarCrossref
Coresh  J , Turin  TC , Matsushita  K ,  et al.  Decline in estimated glomerular filtration rate and subsequent risk of end-stage renal disease and mortality.   JAMA. 2014;311(24):2518-2531. doi:10.1001/jama.2014.6634PubMedGoogle ScholarCrossref
Weitzman  D , Chodick  G , Shalev  V , Grossman  C , Grossman  E .  Prevalence and factors associated with resistant hypertension in a large health maintenance organization in Israel.   Hypertension. 2014;64(3):501-507. doi:10.1161/HYPERTENSIONAHA.114.03718PubMedGoogle ScholarCrossref
Israel Center for Disease Control. Israel national cancer registry. State of Israel Ministry of Health. Accessed February 19, 2021.
Borgan  Ø . Multiple events per subject. In: Therneau TM, Grambsch PM, eds. Modeling Survival Data: Extending the Cox Model. Springer-Verlag; 2000:169-229.
Ali  M , Emch  M , von Seidlein  L ,  et al.  Herd immunity conferred by killed oral cholera vaccines in Bangladesh: a reanalysis.   Lancet. 2005;366(9479):44-49. doi:10.1016/S0140-6736(05)66550-6PubMedGoogle ScholarCrossref
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right

Name Your Search

Save Search
With a personal account, you can:
  • Track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience

Lookup An Activity



My Saved Searches

You currently have no searches saved.


My Saved Courses

You currently have no courses saved.

With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right