Maternal vaccination during pregnancy helps protect babies from being hospitalized due to COVID-19

In a new study sponsored by the Centers for Disease Control and Prevention and published in the New England Journal of Medicine, researchers provide additional evidence that COVID-19 vaccination during pregnancy helps protect babies younger than 6 months from being hospitalized due to COVID-19. The risk of COVID-19 hospitalization among babies was reduced by about 80 percent during the Delta wave (July 1–December 18, 2021) and 40 percent during the Omicron wave (December 19–March 8, 2022).

Our results reinforce the importance of COVID-19 vaccination during pregnancy to protect both the women and their babies from COVID-19. Although protection was lower during the Omicron period, compared to the Delta period, even a moderate reduction in risk is important, because COVID-19 vaccines are not likely to be available for babies younger than 6 months old in the foreseeable future."

Bria Coates, MD, Co-Author, Critical Care physician at Ann & Robert H. Lurie Children's Hospital of Chicago and Assistant Professor of Pediatrics at Northwestern University Feinberg School of Medicine

The study included infants younger than 6 months of age who were admitted to 30 pediatric hospitals in 22 states from July 1, 2021, to March 8, 2022.

Dr. Coates and colleagues found that most infants (90 percent) who needed intensive care due to COVID-19 infection were born to mothers who were not vaccinated during pregnancy.

Infants aged younger than 6 months old are at high risk for complications of COVID-19, including severe respiratory failure or death and account for a disproportionately high percentage of hospitalizations among those aged 0-4 years. This study included data on 537 babies who were hospitalized with COVID-19. Of those, 21 percent were admitted to the intensive care unit and 12 percent required mechanical ventilation, or extra help getting enough oxygen to the body, or vasoactive infusions. Two babies died because of COVID-19 and two required advanced life support that helps the body get enough oxygen; mothers of these babies were not vaccinated.

Researchers also found that effectiveness of maternal COVID-19 vaccination against COVID-19 hospitalization for babies was higher among women vaccinated after 20 weeks of pregnancy, versus early in pregnancy.

"While protection for the baby is important, it is critical to remember that COVID-19 vaccines protect women against severe illness during pregnancy and reduce complications from COVID-19," said Dr. Coates, who also is the Crown Family Research Scholar in Developmental Biology.

When considering the timing of COVID-19 vaccination during pregnancy, the CDC and professional medical organizations, like the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine, recommend COVID-19 vaccination as soon as eligible and at any point in pregnancy. The CDC recommends that women who are pregnant, breastfeeding, trying to get pregnant, or might become pregnant in the future get vaccinated and stay up to date with their COVID-19 vaccines.