MedicalResearch.com Interview with:
Michael Jackson PhD, MPH
Kaiser Permanente Washington Health Research Institute (KPWHRI) principal investigator for the United States Influenza Vaccine Effectiveness Network
MedicalResearch.com: What is the background for this study?
- Response: Each year, Kaiser Permanente Washington is one of five sites across the country that participate in the United States Influenza Vaccine Effectiveness Network. The Network reports its early interim results in the MMWRand presents additional interim results to the Advisory Committee on Immunization Practices (ACIP). This New England Journal of Medicine publication is an update of those interim results.
- The findings in this New England Journal of Medicine are special because prior randomized controlled trials indicated that the nasal spray vaccine (FluMist)—also called live attenuated influenza vaccine (LAIV)—would work well to protect children and teens from the flu, whereas in actual practice we found that the flu shot worked much better, particularly against the predominant strain, A(H1N1)pdm09.
- The nasal spray vaccine was first seen to be less effective for young children than the flu shot in 2013-2014 for the A(H1N1)pdm09 virus strain. In response, the A(H1N1)pdm09 virus strain used in the nasal spray vaccine was changed for the 2015-2016 influenza season. The 2016/17 season was the first since 2015-2016 to be dominated by the A(H1N1)pdm09 virus, making this our first opportunity to evaluate the updated nasal spray vaccine.
- The Influenza Vaccine Effectiveness Network evaluated the impact of this change as part of our estimates of influenza vaccine effectiveness in 2015-2016. Preliminary findings from this study were presented to the ACIP in June 2016, which led to the nasal spray vaccine not being recommended in 2016-2017 in the US, although the nasal spray vaccine remains licensed in the US. In 2016-2017, the LAIV A(H1N1)pdm09 vaccine strain was unchanged from 2015-2016.