Garner-Spitzer et al.
Obesity and sex affect the immune response to tick-borne encephalitis booster vaccination
Front. Immunol. 2020, 11:860, doi.org/10.3389/fimmu.2020.00860
According to the WHO, about 13% of the world population is obese (BMI ≥30 kg/m2: in Europe, 23% were obese in 2016. Obesity has severe health consequences and a substantial impact on immunity and pathogen defense. Given the increased susceptibility to infections in obese individuals, vaccination as a preventive measure is highly important, but the immune response to vaccination is questionable.
An Austrian team has analyzed in an open-label, non-randomized phase IV trial in two groups the booster response of a TBE vaccine based on the Neudörfl strain – 37 obese individuals and 36 normal-weight controls (<25 kg/m2). All participants had received a documented primary TBE vaccination and at least one booster. The immune response was evaluated prior to and 1 week, 4 weeks and 6 months after the booster vaccination. In addition, metabolic, hormonal, and immunologic parameters were determined.
One week after the booster, antibody titers increased by 1.6-fold in both groups, highest titers were reached after four weeks with GMT 503 in the control group and GMT 518 in the obese group. The decline after six months was significantly stronger in the obese group compared to the control group (GMT 229 vs. 310). Overall, the incidence of local reactions to the TBE booster vaccination was similar in both groups, while there was a trend towards increased systemic reactions in obese participants.
Leptin and insulin concentrations were increased in obese individuals. Testosterone was significantly decreased in obese males. Overall, the data observed in this study indicate a complex interplay of the metabolic, endocrine, and immune system under obese conditions, which influenced the booster vaccination. The faster antibody decline rates in obese individuals may lead to a reduced long-term protection and is now investigated in an additional study.