Maternal influenza vaccination and associated infant hospitalizations

According to a study published in JAMA Pediatrics, maternal influenza vaccination during pregnancy resulted in protection for the infant during the first months of life, prior to influenza vaccination eligibility at 6 months of age.

Samantha Olson, MPH, study investigator; epidemiologist, Influenza Division, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, joins Contemporary Pediatrics to break down the purpose of the study and provide detailed results.

Results revealed that vaccine effectiveness was, "highest among hospitalized infants, those younger than 3 months, and those born to mothers vaccinated in the third trimester."

"We saw that infants born to mothers that received influenza vaccination during pregnancy saw a reduction in hospitalizations in emergency department visits by approximately a third," Olson told Contemporary Pediatrics.

Data from the 2016 to 2017 influenza season through the 2019 to 2020 influenza season, just prior to the start of the COVID-19 pandemic, was used in the study.

Since the pandemic, Olson noted, there has been a decline in pregnant persons who have received the influenza vaccine.

"As of December 2023, in the current influenza season, we've seen about a 3% reduction since the last flu season." Olson said.

"When we compare to prior seasons, those prior to [the COVID-19 pandemic], we see about a 17% reduction from the current season to December 2019."

Reference:

Sahni LC, Olson SM, Halasa NB, et al. Maternal vaccine effectiveness against influenza-associated hospitalizations and emergency department visits in infants. JAMA Pediatr. 2024;178(2):176–184. doi:10.1001/jamapediatrics.2023.5639