8. Stress, insomnia and influenza vaccine response

The current analyses were part of a larger two-year study examining the relationship between perceived stress and influenza vaccine antibody responses in a healthy young adult population by comparing people with insomnia to people without insomnia. Self-reported stress levels were assessed in all individuals using the Perceived Stress Scale (PSS). Influenza strains included H1N1, H3N2 and B. Participants gave a blood sample for antibody assessment both before and four weeks after the vaccine. Anti-influenza IgG antibody amounts were measured via ELISA. Correlations were examined between PSS scores (assessed prior to vaccination) and antibody amounts among the various influenza strains both pre- and post-vaccine. Overall, self-reported stress was negatively correlated with antibody levels pre-vaccine for the H1N1 (−.214, p  = .009) and H3N2 (−.243, p  = .003) strains and post-vaccine for H3N2 (−.244, p  = .004) and B (−.186, p  = .028) strains. Results indicated that overall, PSS scores were negatively correlated with anti-influenza antibody (IgG) responses both pre- and post-vaccine for some strains/years, a result that is consistent with a number of studies examining stress and vaccine responses. Interestingly, while people with insomnia self-reported more stress than those without ( p  = .000), covariate analyses examining stress as a predictor of antibody responses pre- to post-vaccine was not significant ( p  > .05).