Pregnant and lactating women were left out of the initial trials of Covid vaccines, so it is not recommended to apply them in this group in a generalized way, leaving the decision to each woman. Assessing risks and benefits, each one decides whether to immunize or not, taking into account particular conditions such as having previous illnesses or being health professionals with a high risk of infection.
Meanwhile, studies were being carried out in pregnant women and we already know the first results, which could change the current recommendations.
Research published yesterday in the American Journal of Obstetrics and Gynecology , the largest study of vaccines in pregnant women to date, concludes that the Pfizer and Moderna vaccines against Covid-19 are effective in pregnant and lactating women , and that they can pass protective antibodies to their newborns.
Researchers from Massachusetts General Hospital, Brigham and Women’s Hospital and the Ragon Institute at MGH, MIT and Harvard observed 131 women who received the Pfizer / BioNTech or Moderna vaccine against Covid-19 between December 17, 2020 and December 2 March 2021.
Higher antibodies in pregnant women
Among the participants, 84 women were pregnant, 31 were lactating, and 16 were not pregnant.
The scientists found that vaccine-induced antibody levels were equivalent in pregnant and lactating women, compared to non-pregnant women.
These antibodies were “surprisingly higher” than those resulting from coronavirus infection during pregnancy.
“These vaccines appear to work incredibly effectively in these women,” said one of the researchers, Galit Alter, a professor of medicine at the Ragon Institute.
Antibodies in the placenta and breast milk
They also found antibodies in umbilical cord blood and breast milk, indicating that women pass protective antibodies to their babies .
“Almost all the moms were getting a pretty decent level of antibodies for their babies,” Alter said. However, he added that more research is needed to find out how long those protective antibodies last in newborns.
While they found similar antibody levels in women vaccinated with both vaccines, they found higher levels of IgA antibodies in pregnant women who received Moderna’s vaccine .
Researchers believe that this particular type of antibody can be transferred more efficiently to babies, over a longer period of time. This could be an aid in deciding which vaccine to recommend for pregnant women.
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