Abstract
BACKGROUND: Concerns about possible side effects are a well-recognized barrier to influenza vaccination and emerging data indicate rates of reactogenicity for inactivated influenza vaccines may vary by manufacturer. We surveyed adults to assess their preference for hypothetical influenza vaccines with equivalent efficacy but differing rates of serious and minor adverse events. RESULTS: The response rate was 94% (1006/1071); 44% of respondents reported receiving influenza vaccine at least once in the past. Seventy-two percent of respondents expressed a preference for vaccines that provided the same level of protection, but were less likely to produce serious side effects, and 55% expressed a preference for vaccines less likely to produce minor side effects. No significant differences by prior influenza vaccination history, age group or gender were identified. CONCLUSIONS: A substantive proportion of adults have a strong preference for influenza vaccine formulations less likely to produce even minor side-effects, such as injection site reactions. Identifying influenza vaccines with equivalent efficacy but lower reactogenicity is important because experience with side effects may negatively impact future vaccine uptake. METHODS: Computer assisted telephone interviews were conducted as part of a population-based survey using a stratified random sample drawn from the residential White Pages® telephone directory.