The study also provided insight into potential differences between the immune response elicited by the two mRNA vaccines created by Pfizer and Moderna.
A recent study conducted by investigators from Massachusetts General Hospital, in collaboration with Brigham and Women's Hospital and the Ragon Institute of MGH, MIT and Harvard, has discovered that COVID-19 mRNA vaccines are highly effective at producing antibodies in pregnant and lactating women.
Results from the study were published in American Journal of Obstetrics and Gynecology (AJOG).
"This news of excellent vaccine efficacy is very encouraging for pregnant and breastfeeding women, who were left out of the initial COVID-19 vaccine trials," Andrea Edlow, co-senior author on the study said. "Filling in the information gaps with real data is key - especially for our pregnant patients who are at greater risk for complications from COVID-19. This study also highlights how eager pregnant and lactating individuals are to participate in research."
Investigators behind the study analyzed 131 women of reproductive age (84 pregnant, 31 lactating and 16 non-pregnant) who had received either the Pfizer or Moderna COVID-19 vaccine.
Findings showed that both of the vaccines induced antibody levels that were equivalent in all 3 groups, with side effects being rare and comparable across the participants of the study. Additional findings showed that the vaccines caused significantly higher levels of antibodies compared to those induced by a natural infection.
Investigators also discovered that the antibodies were present in umbilical cord blood and breastmilk samples, implying that they can be transferred from mother to baby.
"We now have clear evidence the COVID vaccines can induce immunity that will protect infants," Galit Alter, a co-senior author of the study said. "We hope this study will catalyze vaccine developers to recognize the importance of studying pregnant and lactating individuals, and include them in trials. The potential for rational vaccine design to drive improved outcomes for mothers and infants is limitless, but developers must realize that pregnancy is a distinct immunological state, where two lives can be saved simultaneously with a powerful vaccine. We look forward to studying all vaccine platforms in pregnancy as they become available."