Perceived seriousness of seasonal and A(H1N1) influenzas, attitudes toward vaccination, and vaccine uptake among U.S. adults: does the source of information matter?

OBJECTIVE: We estimated uptake of seasonal and 2009 influenza A(H1N1) vaccine among U.S. adults and assessed their perceptions of the seriousness of both types of influenza and corresponding attitudes toward vaccination during the 2009-2010 influenza season. We further documented how vaccine uptake and attitudes varied by main information source used in vaccination decisions. METHODS: We analyzed nationally representative data from U.S. adults age 18 and older (N=3,917) who completed an influenza vaccination survey between March 4th and March 24th, 2010. RESULTS: 2009 influenza A(H1N1) vaccine uptake was considerably lower than seasonal vaccine uptake. While 2009 influenza A(H1N1) was perceived to be more serious than seasonal influenza, the pandemic vaccine was perceived to be less safe than the seasonal vaccine. Vaccine uptake and attitudes displayed large variation between adults who relied on different information sources for making their vaccination decisions. CONCLUSION: The information launched during the response to the 2009 pandemic appear to have generated higher levels of concern about pandemic than seasonal influenza, but did not appear to reassure adults of the safety and value of the pandemic vaccine. Differences in perceived vaccination safety may be an important factor for explaining the lower uptake of pandemic relative to seasonal vaccine.