Altered immunogenicity of 23-valent pneumococcal polysaccharide vaccine in elderly patients with diabetes who revealed lower responses to concomitant administration of BIKEN varicella zoster vaccine: Results of post hoc analysis of a randomized double-blind trial

Aims This double-blind randomized controlled study of 52 elderly patients with diabetes assessed cell-mediated immunity and safety of BIKEN varicella-zoster vaccine (BVZV). Cellular and humoral responses to VZV at 3 months after BVZV and 23-valent polysaccharide pneumococcal vaccine (PPSV23) vaccination elicited poor results. Post-hoc analyses assessed the effects of immunogenicity of PPSV23. Methods Using standardized enzyme-linked immunosorbent assay, pneumococcal 6B and 23F serotype-specific immunoglobulin G (IgG)-binding antibody concentrations were measured in stored samples retrospectively before administration and 3 months after. Responders increased more than twofold in at least one serotype-specific IgG. Results The geometric mean concentration ratio (GMCR) of serum anti-pneumococcal 6B IgG was 1.76 (95%C.I.: 0.58, 5.34) in patients receiving concurrent PPSV23 and BVZV, compared to 2.39 (95%C.I.: 0.53, 10.76) in patients receiving PPSV23 and placebo (P = .055). The GMCR of serum anti-pneumococcal 23F IgG was 2.54 (95%C.I.: 0.57, 11.43) in PPSV23/BVZV vaccinees compared to 3.34 (95%C.I.: 0.84, 12.92) in PPSV23/placebo vaccinees (P = .424). Responder rates, those who developed antibodies to either/both serotypes, were 68% in the BVZV group and 85% in the placebo group (P = .007). Conclusions Results suggest that concurrent administration of BVZV influenced humoral responses to PPSV23 in elderly subjects with diabetes.