A Marshfield Clinic Research Institute study recently found that getting a flu vaccination one year did not reduce vaccine effectiveness the next year in children, findings that support current recommendations for children to be vaccinated annually against influenza.

The study was conducted by Huong McLean, Ph.D., and Edward Belongia, M.D., of the Center for Clinical Epidemiology and Population Health at Marshfield Clinic Research Institute, and was published in JAMA Network Open

“There are many factors that may impact how well the vaccine works each year. A person’s prior exposure to influenza vaccination and infection is an important factor that should be studied,” McLean said.

The three-year study looked at whether or not getting the flu vaccine the prior year reduced the effectiveness of the vaccine in children the following year. Effectiveness of the live attenuated (FluMist nasal spray) and inactivated (flu shot) vaccines were not reduced when children received vaccination in both the current and prior seasons.

McLean was surprised to see differences by vaccine type. Children who received FluMist had much better protection against influenza H3N2 if they had also received the flu vaccine in the prior season. Protection from the flu shot was not affected by vaccination in the prior season.

“We don’t really know why we see these differences, especially during a season that was not a good match,” McLean said. “It is something we are trying to better understand.”

This study was completed during the 2013-2014, 2014-2015 and 2015-2016 flu season by investigators from the Research Institute, Wake Forest School of Medicine, Baylor Scott & White Health, Vanderbilt University Medical Center and MedImmune.

Articles about the study have been published in nbcnews.com, CIDRAP, HealthDay and many other national news organizations.


Articles about the study have been published in CIDRAP and HealthDay.

More information about the study is also available below: