COVID-19 vaccination and boosting during pregnancy benefits pregnant people and newborns
Receiving a COVID-19 mRNA vaccine or booster during pregnancy can benefit pregnant people and their newborn infants, according to findings recently published in Vaccine. The paper describes results from the Multisite Observational Maternal and Infant Study for COVID-19 (MOMI-VAX), which was funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
Researchers at the NIAID-funded Infectious Diseases Clinical Research Consortium (IDCRC) followed more than 500 pregnant volunteers and their newborns, at nine study sites. Results from 240 participants are reported in this paper, including 167 pregnant participants who received the two-dose primary series of either of the two mRNA vaccines during pregnancy, and 73 who received a booster dose; at the time, only one booster dose was recommended. Researchers examined blood samples taken before and after participants were vaccinated or boosted, and at time of delivery. The researchers also analyzed participants’ cord blood at the time of birth.
The researchers found that pregnant people who received the COVID-19 vaccines generated antibodies against specific types of SARS-CoV-2. These included antibodies against the D614G variant (which the vaccines were designed to protect against), as well as the Delta and Omicron subvariants. The antibodies effectively crossed the placenta and were also found in the cord blood of vaccinated participants. This likely conferred some protection in the newborns against these variants immediately after birth—a critical time when they are vulnerable to severe COVID-19 disease but are too young to be vaccinated, according to the researchers.
Pregnant participants who received a booster dose had substantially more antibodies against SARS-CoV-2, both in their own blood and in their cord blood, suggesting that boosting also increased their newborns’ immune defenses against COVID-19. These findings support the use of COVID-19 vaccination, and in particular booster doses, during pregnancy for protection of mothers and newborns.
