Effect of obesity in children on the response to influenza virus vaccination (639.6)

Obesity is a global health concern and more than one‐third of the adult population in the United States is obese. Childhood obesity is also on the rise, with obesity rates doubling in children over the past 30 years and tripling in adolescents. Obese adults are at greater risk for increased severity of infections with influenza virus and obesity has recently been found to be an independent risk factor for increased morbidity and mortality from influenza infection. Vaccination with influenza virus vaccine is the best method to protect from or lessen infection with influenza. However, studies in our laboratory have demonstrated that obese adults, when compared with healthy weight adults, have a suboptimal response to influenza vaccination. To expand our findings to children, we enrolled children, ages 2‐17 with a range of BMI percentiles to study the effect of weight status on the response to influenza vaccination. We collected a pre‐vaccination blood sample, and 30 days later, a post‐vaccination blood sample. Peripheral blood mononuclear cells were isolated and stimulated ex vivo with pH1N1 influenza virus, a strain present in the vaccine, and markers of activation and inflammation were measured by flow cytometry. We found that obese children displayed a significant decrease in the CD4+ T cell activation marker CD69, which may suggest that obese children may have a poorer response to influenza infection compared with healthy weight children. In addition, we found that unstimulated T cells from obese children had increased markers of inflammation, including IFNγ and granzyme B, when compared to healthy weight children, suggesting that PBMCs from obese children may not respond appropriately when challenged with antigen. Therefore, much like the obese adult population, obese children also have immune impairments that may put them at greater risk for infections, even when vaccinated. Grant Funding Source : NC TraCS Institute