COVID-19 Vaccines are Safe During Pregnancy, Says Study

Study finds Moderna and Pfizer vaccines safe for use during pregnancy and lactation. Source: Shutterstock.

A recently published study has found Pfizer/BioNTech and Moderna COVID-19 vaccines safe and effective for use during pregnancy and lactation.

According to the Centers for Disease Control and Prevention (CDC), more than 70,000 infections and 80 deaths have occurred in pregnant women during the pandemic. Moreover, pregnant women have an increased risk of infection, ICU stay, COVID-19 complications, and death. However, despite the increased risk, researchers have largely left out pregnant and lactating women from vaccine trials. Therefore, a team of researchers aimed to investigate whether COVID-19 vaccines are safe during pregnancy and lactation. The team comprised of researchers from Massachusetts General Hospital, Brigham and Women’s Hospital, and the Ragon Institute of MGH, MIT and Harvard.

The research published in the American Journal of Obstetrics and Gynecology (AJOG), is the largest study on vaccines and pregnancy. Researchers recruited a total of 131 participants: 16 non-pregnant women, 84 pregnant, and 31 lactating. All had received either the Pfizer/BioNTech or Moderna vaccine.  

This news of excellent vaccine efficacy is very encouraging for pregnant and breastfeeding women, who were left out of the initial COVID-19 vaccine trials. Filling in the information gaps with real data is key – especially for our pregnant patients who are at greater risk for complications from COVID-19.

Andrea Edlow, co-senior author of the new study 

Antibodies Found in Umbilical Cord

The findings of the study revealed equal levels of vaccine-induced antibodies in all three groups. In comparison to natural infection, the immune response from vaccines was significantly greater. Moreover, researchers also found vaccine-induced antibodies in all umbilical cord blood and breastmilk samples. Thus, providing evidence of the transfer of antibodies via placenta and breastmilk.

Women in all three groups suffered similar side effects. These included headaches, pain at the injection site, and rashes. There was no difference in the severity or frequency of these side effects among the groups.

Furthermore, the study also provided insight into the difference in immune responses elicited by Pfizer and Moderna. Results showed that compared to Moderna, a second dose of Pfizer vaccine induced a greater amount of IgA antibodies.

We now have clear evidence the COVID vaccines can induce immunity that will protect infants. We hope this study will catalyze vaccine developers to recognize the importance of studying pregnant and lactating individuals and include them in trials.

Galit Alter, co-senior author of the study

Recently, a vaccinated woman in Florida gave birth to a baby with COVID-19 antibodies. Researchers believe it is the first case confirming that maternal vaccination provides protection for newborns. Coupled with the findings of the new study, there is increasing evidence of vaccinations being safe and effective for pregnant women.


Gray KJ, Bordt EA, Atyeo C, Deriso E, Akinwunmi B, Young N, Medina Baez A, Shook LL, Cvrk D, James K, De Guzman R, Brigida S, Diouf K, Goldfarb I, Bebell LM, Yonker LM, Fasano A, Rabi SA, Elovitz MA, Alter G, Edlow AG, COVID-19 vaccine response in pregnant and lactating women: a cohort study, American Journal of Obstetrics and Gynecology (2021), doi:


Please enter your comment!
Please enter your name here