Maternal COVID-19 vaccination: A powerful safeguard for infants younger than 6 months

Maternal receipt of a COVID-19 vaccine during pregnancy offers robust protection for infants younger than six months. These findings were published in the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report.

“This study shows us that moms who received one or more COVID vaccines in their pregnancy were at decreased risk for having a baby less than 6 months of age in the hospital with COVID,” said Elizabeth Mack, M.D., a pediatric critical care physician who led the Medical University of South Carolina site of the study.

"This study shows us that moms who received one or more COVID vaccines in their pregnancy were at decreased risk for having a baby less than 6 months of age in the hospital with COVID."

-- Dr. Elizabeth Mack

This observation, grounded in data from numerous hospitals, highlights the potential of maternal vaccination in protecting the youngest members of our population from severe outcomes.

The Overcoming COVID-19 study revealed that infants born to women who had received the COVID-19 vaccine while pregnant were hospitalized less frequently due to COVID-19 than infants born to unvaccinated mothers. Specifically, the maternal vaccine reduced hospitalizations by 35% for infants under 6 months and an impressive 54% for those under 3 months. This finding is particularly welcome because babies younger than 6 months are not currently eligible for COVID-19 vaccination.

Among the 377 newborns diagnosed with COVID-19 in the study, 86 were admitted to an intensive care unit (ICU). Of those, 50 required life support. Importantly, 84% of these critically ill infants had mothers who were not vaccinated. Infants born to unvaccinated mothers were also nine times more likely to need invasive mechanical ventilation, also known as ventilator support.

The study was conducted by the Overcoming COVID-19 Network, a consortium of researchers at children’s hospitals across the nation who work together to answer questions about COVID-19 in kids. The MUSC Shawn Jenkins Children’s Hospital was one of more than 20 hospitals that contributed data to this study.

 

Perhaps most notably, the study highlighted that most hospitalized infants had been healthy before COVID-19 infection, underscoring the importance of maternal vaccination in providing early-life protection against severe COVID-19 disease.

The finding that maternal vaccination protects newborns from severe disease aligns with Mack’s own experience in the pediatric ICU.

“It is quite rare that I see a baby born to a vaccinated mother become critically ill with COVID,” Mack said.

The Overcoming COVID-19 study emphasizes the importance of expectant mothers staying up to date with their COVID-19 vaccinations, especially as hospitalization rates for newborns with COVID-19 remain high. Up-to-date vaccines not only protect the mothers but also extend crucial protection to their infants, preventing hospitalization and reducing the likelihood of severe outcomes.

“Remember, the job of the COVID vaccine is to prevent hospitalization and death, and it does that job incredibly well,” said Mack.

Reference

Simeone RM, Zambrano LD, Halasa NB, et al. Effectiveness of Maternal mRNA COVID-19 Vaccination During Pregnancy Against COVID-19–Associated Hospitalizations in Infants Aged <6 Months During SARS-CoV-2 Omicron Predominance — 20 States, March 9, 2022–May 31, 2023. MMWR Morb Mortal Wkly Rep 2023;72:1057–1064. DOI: http://dx.doi.org/10.15585/mmwr.mm7239a3