COVID Vaccines Trigger Strong Immune Responses In Pregnant, Lactating Women, Newborns

COVID-19 vaccinations can induce a strong immune response in pregnant women who then pass the antibodies to their babies through the placenta and breast milk, a study has found.

The study by researchers at Brigham and Women's Hospital and Massachusetts General Hospital and published in the American Journal of Obstetrics and Gynecology included the blood and breast milk of 131 women of reproductive age, including 84 pregnant, 31 lactating and 16 who were not pregnant.

The women received two doses of either the Pfizer/BioNTech or Moderna vaccine between Dec. 17 and March 2.

The investigators found antibody levels induced by the vaccine were uniformly high in all three groups of women. "COVID vaccination in pregnancy and lactation generated robust humoral immunity similar to that observed in nonpregnant women with similar side effect profiles," the authors said.

The findings are consistent with data presented in other preliminary studies as well as a recent report by the Centers for Disease Control and Prevention, which is monitoring for vaccine-related side effects through its v-safe mobile app and has a registry specially for pregnant women.

Scientists suspect vaccines would be safe and effective in pregnant and breastfeeding mothers but they didn't have hard evidence because these women were exempt from trials, according to Live Science.

The new study is an important "first step" to confirming the positive results that scientists anticipated, according to Dr. Stephanie Gaw, an assistant professor of obstetrics, gynecology, and reproductive sciences at the University of California, San Francisco.

The new research only looked at the Moderna and Pfizer vaccines. Both vaccines contain a genetic material that encodes instructions for cells to create proteins.

The COVID-19 vaccines do not always use this material. The Johnson & Johnson shot uses a modified common cold virus. Future research will be needed to test these treatments in pregnant women.