Impact of Maternal Influenza Vaccination During Pregnancy

A recent study exploring the impact of maternal influenza vaccination during pregnancy has shown promising outcomes in reducing influenza-related hospitalizations and emergency department (ED) visits in infants under 6 months of age. The study, conducted using data from the New Vaccine Surveillance Network across multiple influenza seasons, sheds light on the protective benefits of maternal vaccination against influenza-associated illnesses in young infants.

The study was published in the journal of JAMA Pediatrics by Leila Sahni and colleagues. The study included 3764 infants, among whom 53% were born to mothers who received influenza vaccination during pregnancy. The overall effectiveness of maternal vaccination in infants against influenza-related hospitalizations and ED visits was estimated at 34%. Specifically, the vaccine demonstrated a 39% effectiveness in preventing hospitalizations and a 19% effectiveness in mitigating ED visits associated with influenza.

Among infants younger than 3 months, the effectiveness of maternal vaccination soared to 53%, indicating a stronger protective effect in this vulnerable age group. Notably, infants born to mothers vaccinated during the third trimester exhibited a higher effectiveness rate of 52%, whereas those whose mothers were vaccinated during the first or second trimesters showed a lower effectiveness rate of 17%.

The study's findings underscore the significance of maternal influenza vaccination during pregnancy in reducing the risk of influenza-associated hospitalizations and ED visits in infants below 6 months of age. The observed effectiveness was particularly notable in younger infants and those born to mothers vaccinated during the later stages of pregnancy.

These results emphasize the importance of promoting maternal influenza vaccination as a crucial preventive measure to safeguard both maternal and infant health. Encouraging vaccination, especially during the third trimester, could offer substantial protection against influenza-related complications in vulnerable newborns.

Reference

Sahni, L. C., Olson, S. M., Halasa, N. B., Stewart, L. S., Michaels, M. G., Williams, J. V., Englund, J. A., Klein, E. J., Staat, M. A., Schlaudecker, E. P., Selvarangan, R., Schuster, J. E., Weinberg, G. A., Szilagyi, P. G., Boom, J. A., Patel, M. M., Muñoz, F. M., McNeal, M., Rohlfs, C., … New Vaccine Surveillance Network Collaborators. Maternal vaccine effectiveness against influenza-associated hospitalizations and emergency department visits in infants. JAMA Pediatrics, 2023. https://doi.org/10.1001/jamapediatrics.2023.5639