The Pfizer and Moderna vaccines are safe and effective in pregnant and lactating women and those women are able to pass protective antibodies to their newborns, according to a new study.
To come to that conclusion, researchers studied a group of 131 reproductive-age women who received the Pfizer or Moderna vaccine, including 84 pregnant, 31 lactating and 16 non-pregnant women and found antibody levels were similar in all three groups.
“That’s a very important piece of information to our patients,” said Dr. Andrea Edlow, co-author on the study which was published in the American Journal of Obstetrics & Gynecology on Thursday.
“We know that this vaccine works for you.” Another common concern among pregnant patients is vaccine side effects. The study found no significant difference in vaccine side effects between pregnant and non-pregnant study participants.
Compared to pregnant women who had recovered from COVID, pregnant women who received the vaccine had “strikingly higher” antibody levels. Interestingly, women who received the Moderna version had greater antibody levels than those who received the Pfizer.
Vaccine-generated antibodies were present in all of the umbilical cord and breast milk samples that were tested, which suggests that pregnant and lactating women pass COVID-19 protection to their fetuses or newborns.
“That is the most comforting piece of information that’s out there,” said Galit Alter, study author and professor of medicine at the Ragon Institute.
The antibodies that researchers found in the mother’s blood were what’s known as neutralizing, meaning they have the ability to kill SARS-CoV-2 in laboratory tests, but more research needs to be done to determine whether infants have robust immunity after receiving antibodies from their vaccinated mothers.
Future research could also help women decide when the ideal time in pregnancy to get a vaccine is for maximum protective benefits and determine whether other vaccines, like Johnson & Johnson and AstraZeneca, perform similarly to the two in the study.