Scientists have accumulated a small but steadily growing body of evidence that the covid vaccines are safe and effective during pregnancy. Preliminary results from two continuing studies provide additional encouraging news.
The Pfizer-BioNTech and Moderna vaccines produce robust immune responses in pregnant and lactating women and are likely to provide at least some protection against two dangerous coronavirus variants, according to a study published in JAMA.
Vaccinated women can also pass protective antibodies to their fetuses through the bloodstream and to their infants through breast milk, the research suggests.
Covid presents serious risks during pregnancy. Research has shown, for instance, that pregnant women with coronavirus symptoms are more likely to be admitted to the intensive care unit, require mechanical ventilation and to die from the virus than are symptomatic women of a similar age who are not pregnant.
Because of these risks, the Centers for Disease Control and Prevention has recommended that the covid vaccines at least be made available to pregnant people, many of whom have opted to receive the shots.
The researchers also found neutralizing antibodies in the breast milk of vaccinated mothers and in umbilical cord blood collected from infants at delivery. “Vaccination of pregnant people and lactating people actually leads to transfer of some immunity to their newborns and lactating infants,” said Dr. Ai-ris Y. Collier, a physician-scientist at Beth Israel who is the first author of the paper.
The results are “really encouraging,” Dr. Iwasaki said. “There is this added benefit of conferring protective antibodies to the newborn and the fetus, which is all the more reason to get vaccinated.”
The study will continue, with researchers monitoring women’s longer-term immune responses. And larger epidemiological studies are still needed to confirm these lab-based results, Dr. Collier noted.