The pivotal trial Pfizer used to win emergency use authorization for the vaccine excluded pregnant women. COVID-19, however, increases the risk of pregnancy-related complications — particularly in the third trimester.
To determine how the vaccine performs in pregnant women, researchers in Israel tracked 7,530 vaccinated and 7,530 unvaccinated expectant mothers. They counted 118 COVID-19 infections in the vaccinated group and 202 in the control group. Researchers recruited volunteers from Maccabi Healthcare Services (Tel Aviv).
Among the two groups of women with PCR-confirmed COVID-19 infections, between 83% and 84% were symptomatic.
Some 68 patients receiving the vaccine complained of adverse events. None of them, however, were severe.
The researchers concluded that pregnancy leads to changes in hormones and immune function that can make women more susceptible to viral infections.
In February, Pfizer and BioNTech announced they were launching a Phase 2/3 study to test the vaccine’s efficacy in pregnant women.
Filed Under: clinical trials, Drug Discovery, Infectious Disease