Effectiveness is encouraging, but updates are needed
The effectiveness of maternal vaccination to prevent COVID-19 infection and related hospitalizations in infants is promising, especially since those younger than 6 months have no other source of vaccine protection against COVID-19 infection, wrote Dana Danino, MD, of Soroka University Medical Center, Israel, and Ilan Youngster, MD, of Shamir Medical Center, Israel, in an accompanying editorial also published in The BMJ.
They also noted that maternal vaccination during pregnancy is an established method of protecting infants from infections such as influenza and pertussis.
Data from previous studies show that most infants whose mothers were vaccinated against COVID-19 during pregnancy retained maternal antibodies at 6 months, “but evidence for protection against neonatal COVID-19 infection has been deficient,” they said.
The current study findings support the value of vaccination during pregnancy, and the findings were strengthened by the large study population, the editorialists wrote. However, whether the same effectiveness holds for other COVID-19 strains such as BQ.1, BQ.1.1, BF.7, XBB, and XBB.1 remains unknown, they said.
Other areas in need of exploration include the optimal timing of vaccination during pregnancy, the protective effects of a bivalent mRNA vaccine (vs. the primary monovalent vaccine in the current study), and the potential benefits of additional boosters, they added.
“Although Jorgenson and colleagues’ study reinforces the value of maternal vaccination against COVID-19 during pregnancy, more studies are needed to better inform vaccination recommendations in an evolving landscape of new SARS-CoV-2 strains and novel vaccines,” the editorialists concluded.
The study was supported by ICES, which is funded by an annual grant from the Ontario Ministry of Health and the Ministry of Long-term Care; the study also received funding from the Canadian Immunization Research Network and the Public Health Agency of Canada. Dr. Jorgensen and the editorialists had no financial conflicts to disclose.
*This article was updated on 3/2/2023.