Statistical modeling using early markers of innate immunity to explain variation in humoral responses to influenza vaccine in older adults.

Greater understanding of the factors associated with a protective response to influenza vaccine in older adults could have tremendous public health benefits. We studied 158 participants age 50-74 years vaccinated with 2010-2011 inactivated influenza vaccine and performed innate immunity and humoral immunity assays directed against influenza A/California/2009 (H1N1) as measured through hemagglutination inhibition (HAI), microneutralization, and B cell ELISPOT at days 0, 3, and 28 postvaccination. We report the results of statistical modeling using Day 3 cytokines, chemokines, and innate cell populations to model Day 0 to Day 28 HAI seroconversion, viral neutralization seroconversion, and B cell ELISPOT results.