Immune response in highly active young men to the 2014/2015 seasonal influenza vaccine

During the 2009 H1N1 pandemic, individuals with obesity were disproportionately affected by H1N1 with increased levels of mortality and morbidity. This led to questions regarding the potential impact of lifestyle on the effectiveness of immunization. Currently, the research is limited on influenza vaccination and the associated changes in immune response with body composition and physical activity. The purpose of this pilot study was to investigate the potential role of adiposity and physical activity in the immune response elicited by the 2014/2015 seasonal trivalent influenza vaccine. A prospective cohort study examining the 2014/2015 seasonal trivalent influenza vaccine was conducted by collecting baseline and 4-week postvaccination fasting blood samples from 45 male Albertans between the ages of 18 and 35 years. Percent body fat (%BF) was assessed through dual X-ray absorptiometry imagining and physical activity through self-reported survey scores. While no differences in median %BF were associated with seroconversion rates in participants, the median physical activity score was higher among those that did not seroconvert to the vaccine. Significant differences were found for the A/Texas strain (p < 0.01) and a similar trend of lower magnitude observed for the remaining 2 influenza strains. These results suggest that higher physical activity levels may influence immune response to vaccination and that assessing factors beyond those commonly used can be of value when identifying vaccine response in the population.