Better Responses Seen With Booster mRNA COVID-19 Vaccine in Pregnancy

FRIDAY, Aug. 18, 2023 (HealthDay News) -- Robust antibody responses to mRNA COVID-19 vaccines are detected in boosted pregnant individuals, according to a study published in the Aug. 14 issue of Vaccine.

Flor M. Munoz, M.D., from the Baylor College of Medicine in Houston, and colleagues conducted a prospective cohort study of participants vaccinated during pregnancy with primary or booster COVID-19 vaccines from July 2021 to January 2022 at nine academic sites. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binding and live virus and pseudovirus neutralizing antibody (nAb) titers were determined prevaccination and postvaccination and at delivery for maternal and infant participants. In maternal sera at delivery and in cord blood, immune responses to ancestral and omicron BA.1 SARS-CoV-2 strains were compared for primary and booster vaccine recipients.

Two hundred forty participants received a Pfizer or Moderna mRNA vaccine during pregnancy (167 primary series; 73 booster). The researchers found that significantly higher binding and nAb titers, including to the omicron BA.1 variant, resulted from booster vaccination compared with the primary two-dose series in both maternal sera at delivery and in cord blood. At delivery, live virus nAb to omicron BA.1 were present in 9 and 22 percent of Pfizer and Moderna primary series recipients, respectively, and in 73 percent of boosted participants. For all regimens, transplacental antibody transfer was efficient.

"Our study supports that COVID-19 vaccination, and particularly booster doses, should be strongly recommended during pregnancy for maternal and neonatal protection," the authors write.

Several authors disclosed ties to the pharmaceutical industry.

Abstract/Full Text