Elderly men with moderate and intense training lifestyle present sustained higher antibody responses to influenza vaccine

We aimed to verify whether different levels of training performed regularly and voluntarily for many years could have an impact on one of the main issues of immunosenescence: the poor response to vaccines. We recruited 61 healthy elderly men (65–85 years old), 23 with a moderate training (MT) lifestyle (for 17.0 ± 3.2 years), 22 with an intense training (IT) lifestyle (for 25.9 ± 3.4 years), and 16 without a training lifestyle (NT). Fitness was evaluated through the IPAQ and VO₂max consumption. The participants were evaluated regarding cognitive aspects, nutritional status, depression, and quality of life. Antibody titers were determined by hemagglutination inhibition assay prior to influenza vaccination and at 6 weeks and 6 months post-vaccination. Strains used were B, H3N2, and H1N1. Our groups were matched for most characteristics, except for those directly influenced by their lifestyles, such as BMI, VO₂max, and MET. In general, MT and IT elderly men showed significantly higher antibody titers to the three vaccine strains post-vaccination than NT elderly men. There were also higher titers against B and H1N1 strains in the trained groups before vaccination. Additionally, there were higher proportions of seroprotected (titers ≥1:40) individuals in the pooled trained groups both at 6 weeks (B and H3N2, p < 0.05) and 6 months (H1N1, p < 0.05; B, p = 0.07). There were no significant differences between the MT and IT groups. Either a moderate or an intense training is associated with stronger and longstanding antibody responses to the influenza vaccine, resulting in higher percentages of seroprotected individuals.