B cells, plasmablasts, CD4 and CD8 T cells, NK cells, and conventional and plasmacytoid dendritic cells were phenotyped in freshly collected whole blood samples
B cells, plasmablasts, CD4 and CD8 T cells, NK cells, and conventional and plasmacytoid dendritic cells were phenotyped in freshly collected whole blood samples. (HAI) and microneutralization (MN) assays. Immunological responses across frailty strata were also studied in terms of leukocyte Rabbit Polyclonal to E2F6 cellular distribution, cytokine levels and gene expression. Results: Post-vaccination, 83.4% of the subjects seroconverted for A/H1N1, 80.5% for A/H3N2, and 81% for the B strain. The seroconversion rates were comparable across frailty groups (A/H1N1, ANOVA, = 0.7910; A/H3N2, ANOVA, = 0.8356, B, ANOVA, = 0.9741). Geometric mean titres of HAI and MN as well as seroprotection rates were also similar in all three frailty groups and uncorrelated with RFI (Spearman, = 0.023, = Tecadenoson 0.738). No statistically significant differences were observed between the frailty groups in vaccine-induced modulation of leukocyte populations, cytokine responses, and gene expression profiles of peripheral blood mononuclear cells (PBMCs). Whereas, post- and pre-vaccination HAI titres were positively correlated after adjusting for age and Tecadenoson gender (A/H1N1, = 9.1e?11; A/H3N2, = 3.4e?8; B, = 3.1e?5). With most subjects lacking previous history of influenza vaccination, the pre-vaccination titres were likely due to natural exposure and seen to match the pattern of influenza subtype prevalence in the time period of vaccination. Conclusion: The majority of the elderly subjects seroconverted for seasonal influenza upon vaccination, and importantly, influenza vaccination-induced humoral immune responses and seroprotection were similar across the frailty strata, indicating that frail individuals may also benefit from influenza vaccination. Pre-existing antibodies due to natural exposure appeared to positively influence vaccine-induced antibody responses. individuals pose a higher degree of risk toward disease and mortality as compared to or individuals (4). Frailty is measured in multiple dimensions including weight loss, weakness, exhaustion, slowness, low physical activity, cognitive impairment, and other health symptoms that would indicate increased vulnerability toward adverse health outcomes (5, 6). Frailty has been shown to influence the course and outcomes of health conditions (7). However, it is not clearly understood whether differences exist between frail and non-frail elderly in their capacity to respond to influenza vaccination, as there are conflicting reports in the literature. While some earlier studies reported reduced humoral responses to influenza vaccine in the frail, (8C10), more recent studies have not supported these findings (11C15). It is important to understand whether frailty has a significant impact on vaccine-induced immunity as this information might guide policy decisions on relevant aspects such as the frequency, dosage and composition of influenza vaccine administered to the elderly and could have an impact on future rational vaccine design strategies. In this study, immune responses to seasonal influenza vaccination were assessed in an Asian cohort of elderly Chinese Singaporeans stratified by frailty. In addition to assessing the humoral response, which typically comprises the primary endpoint of vaccine responsiveness studies, cell mediated immunity which plays a vital role in immunity toward influenza especially in the elderly (16, 17), markers of innate immune responses, cytokine profiles, and time course transcriptomic profiles of peripheral blood mononuclear cells (PBMCs) were also measured. No significant differences were observed between the frail and non-frail groups in their responsiveness to influenza Tecadenoson vaccination in both early and late phases of immune response as well as in the final outcome of virus neutralization. Tecadenoson Methods Recruitment of study participants A phase IV clinical trial of Sanofi Pasteur’s Vaxigrip? influenza vaccine was approved by the National Healthcare Group’s Domain Specific Institutional Review Board and.