COVID-19 vaccines highly immunogenic in pregnant and lactating women, study shows
Both messenger RNA COVID-19 vaccines available in the United States trigger immune responses in pregnant and nonpregnant women, including those who are lactating, researchers reported in JAMA.
Dan H. Barouch, MD, PhD, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in New York, and colleagues conducted an exploratory, descriptive, prospective cohort study among 103 women aged 18 to 45 years who received an mRNA COVID-19 vaccine from December through March, or who had COVID-19 from April 2020 to March 2021.
Among the 103 participants, 30 were pregnant, 16 were lactating. Samples were obtained a medium of 21 days (interquartile range [IQR], 17-27 days) after the second dose from nonpregnant women, 21 days (IQR, 14-36 days) from pregnant women and 26 days (IQR, 19-31 days) from lactating women. Nine pregnant women gave birth during the trial and offered their infant’s cord blood.
Among all trial participants, 56 (54%) had received the Pfizer-BioNTech vaccine and the rest received the Moderna vaccine. Five pregnant participants (17%) received their first dose during their first trimester, 15 (50%) in their second and 10 (33%) in their final trimester.
The authors reported humoral and cellular immune response against wild-type SARS-CoV-2 strain and the Alpha and Beta variants.
According to the findings, two doses of the vaccines produced similar levels of antibody function and T-cell responses in all participants after their second vaccine dose, and all participants developed cross-reactive immune responses against the Alpha and Beta variants. Moreover, the researchers found that mothers transferred antibodies to infant cord blood and breast milk.
“Our data show that the mRNA vaccines are highly immunogenic in pregnant and lactating women, and that vaccinated women may transfer antibodies to their infants by cord blood and breastfeeding,” Barouch told Healio. “These findings, together with other data in the field, support the use of COVID-19 vaccines in pregnant and lactating women.”