NIH study assessing COVID-19 vaccine in pregnant, postpartum moms

NIH study assessing COVID-19 vaccine in pregnant, postpartum moms

The National Institutes of Health launched a new observational study to evaluate the immune responses generated by COVID-19 vaccines in pregnant and postpartum individuals. The study, dubbed MOMI-VAX, will also assess vaccine safety and the transfer of vaccine-induced antibodies through breast milk. 

“Tens of thousands of pregnant and breastfeeding people in the United States have chosen to receive the COVID-19 vaccines available under emergency use authorization,” Dr. Anthony Fauci, director of National Institute of Allergy and Infectious Diseases (NIAD), which is funding the study, said in a news release. “However, we lack robust, prospective clinical data on vaccination in these populations. The results of this study will fill gaps in our knowledge and help inform policy recommendations and personal decision-making on COVID-19 vaccination during pregnancy and in the postpartum period.” 

The study will enroll up to 750 pregnant people and 250 postpartum individuals who are within two months of delivery and have received or will receive a COVID-19 vaccine. The infants will also be enrolled in the study. Researchers will follow the pairs through the first year after delivery and analyze blood samples regularly collected to assess development and durability of vaccine-induced antibodies. 


Mothers will also have the option of submitting breast milk samples at two weeks, two months, six months and 12 months after delivery to evaluate breast milk antibodies. 

Prior studies have found evidence of antibody transfer through the placenta following vaccination, as well as through breast milk, but work is ongoing. Data recently released by the Centers for Disease Control and Prevention (CDC) found pregnant women are getting vaccinated at lower rates than nonpregnant people, particularly younger populations. Of 136,000 pregnant women identified in the data, just 11.1% had completed vaccination. 


Pregnant people are at an increased risk for severe illness from COVID-19 when compared to nonpregnant people, and at increased risk for preterm birth or other poor pregnancy outcomes. When the COVID-19 vaccines received emergency use authorization from the FDA, the panel noted that not enough data was included in clinical trials on pregnant women. Currently, the CDC advises that pregnant people can receive a COVID-19 vaccine.