COVID-19 vaccines, specifically Pfizer/BioNTech and Moderna, have been proven effective in pregnant and lactating women. And the good news is, these women can even pass on those protective antibodies to their newborns, a study published in the American Journal of Obstetrics and Gynecology said on Thursday (COVID-19 vaccine response in pregnant and lactating women: a cohort study).

The study, with samples collected between December 17, 2020 and March 2, 2021, focused on 131 women who took either the Pfizer/BioNTech or the Moderna vaccine. Eighty-four of the women were pregnant, while 31 were lactating and 16 were not pregnant.

COVID19 Vaccines Protecting Both Mother and Baby

Antibody levels induced by the vaccines were equivalent in the pregnant and lactating women, in comparison to the non-pregnant. These levels were "strikingly higher" than those that came about from a coronavirus infection during pregnancy, researchers noted.

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The passed-on antibodies to their babies were measured in breast milk and the placenta. Additional research, however, is being sought to determine how long these antibodies last in their babies.

Research revealed that pregnant and lactating mothers who received the Pfizer/BioNTech and Moderna vaccines get better protection from COVID-19.
(Photo: Photo by Mario Tama/Getty Images) Research revealed that pregnant and lactating mothers who received the Pfizer/BioNTech and Moderna vaccines get better protection from COVID-19.

In an interview on NBC's "TODAY" show, study co-author Dr. Andrea Edlow was ecstatic, saying it was "great news" that their research would provide "evidence-based counseling around the vaccine."

Participants in the study utilized the V-safe tool from the US Centers for Disease Control and Prevention that allows the vaccine recipients to monitor their reaction. Researchers said no evidence of side effects was observed in the pregnant and lactating women more than those seen in the general population.

As women vaccinated with Pfizer/BioNTech and Moderna had similar antibody levels, researchers discovered elevated levels of IgA antibodies in the pregnant women who took the Moderna vaccine. They note that this type of antibody may be passed on to their newborns more efficiently.

Policy Guidance on Vaccines for Pregnant Women

These findings, they said, should help policymakers in determining which vaccines are to be used for pregnant women.

Previous studies also noted that mRNA vaccines produce antibodies in pregnant women that are transferred to their newborns, but this particular study is the most comprehensive on vaccines given to pregnant women to date. During the clinical trials of the vaccines, pregnant and lactating women were left out.

Because no data was available to help pregnant women make informed decisions on their choice of COVID-19 vaccines, researchers, together with healthcare workers, pregnant women, and new mothers, took it upon themselves to spread the word.

The CDC noted that expectant mothers with COVID-19 are at extreme risk for a serious ailment and could be at a higher risk for an adverse outcome, such as a pre-term birth. The US health protection agency added that it is looking forward to a study on vaccine safety for approximately 13,000 pregnant women for each of the available coronavirus vaccines. The CDC will utilize a V-safe pregnancy registry for its planned study, targeting around 3,612 expectant mothers, as of March 22.

According to researchers, the initiative is urgent since such a prospect would protect not only the mother but her newborn, as well.

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