The Pfizer / BioNTech and Moderna COVID-19 vaccines are safe and highly effective in producing antibodies against the SARS-CoV-2 virus during pregnancy, according to a new study. It also appears that some of the protective antibodies can be transmitted to fetuses through the placenta and to newborns through breast milk.
In the largest study on vaccines and pregnancy to date, scientists from Harvard, MIT, Massachusetts General Hospital (MGH), Brigham and Women’s Hospital, and the Ragon Institute at MGH, MIT, and Harvard report their findings in the American Journal of Obstetrics and Gynecology. They looked at 131 women in the US who received the Pfizer / BioNTech or Moderna COVID-19 vaccine, of whom 84 were pregnant, 31 were lactating, and 16 were not pregnant.
Although it is a very small group, it is very promising news. Equal levels of COVID-19 vaccine-induced antibodies were found in pregnant and lactating women, compared to non-pregnant women. Antibodies generated by the vaccine were present in all umbilical cord blood, indicating that they were being transmitted to the fetus, and breast milk samples, indicating that they were being transmitted to nursing babies.
The data also showed no significant difference in post-vaccination reactions in pregnant and non-pregnant women, implying that the vaccines are safe to receive during pregnancy.
Pregnant and lactating women were not included in the initial trials of the COVID-19 vaccine, meaning there was no hard data on whether it was safe or effective. Considering that people who are pregnant are at a higher risk of contracting COVID-19, there was also a real need to see if the vaccine was still effective.
This limited evidence also led to misinformation on social media, with some falsely claiming COVID-19 mRNA vaccines. could cause fertility problems and impact on pregnancy. Scientists never seriously considered these ideas, but they did spread an understandable concern among people looking to start a family in the near future. This new study should allay some of those fears.
“This news of the excellent efficacy of the vaccine is very encouraging for pregnant and lactating women, who were left out of the initial trials of the COVID-19 vaccine,” Andrea Edlow, co-lead author of the new study, specialist in Medicine Maternal Fetal at MGH, and director of the Edlow Laboratory at the Vincent Center for Reproductive Biology, said in a statement.
“Filling the information gaps with real data is key, especially for our pregnant patients who are at increased risk of complications from COVID-19. This study also highlights how eager pregnant and lactating people are to participate in the research. “
Currently, the US Centers for Disease Control and Prevention. (CDC) cautions that the question of whether pregnant women should receive the COVID-19 vaccine is a matter of “personal choice.” While acknowledging that there is currently limited data on the safety of COVID-19 vaccines in pregnant people, they note that “experts believe they are unlikely to pose a specific risk to pregnant people.”
The UK Government has been more cautious, issuing the advice: “Vaccines have not yet been tested during pregnancy, so until more information is available, pregnant women should not receive this vaccine routinely.”
Fortunately, this vital information is now beginning to emerge. The CDC is currently recruiting people to join the v-safe pregnancy registry collect information on the health of pregnant women who have received the COVID-19 vaccine.