Shingles vaccine booster shots appear safe and restimulate immunity years later
A new trial shows that adults who received the recombinant zoster vaccine can safely get booster shots five to six years later, with antibody levels spiking back up after each dose. The findings could reshape vaccination schedules for older adults and inform manufacturers' recommendations on revaccination timing.
Originaltitel: Safety and immunogenicity of one or two additional doses of the adjuvanted recombinant zoster vaccine administered 5–6 years after primary vaccination in adults ≥50 years
Abstract Background A phase 3b extension of the ZOE-50/70 trials evaluated long-term efficacy, immunogenicity, and safety of the recombinant zoster vaccine (RZV) in participants ≥50 years, with a 6-year follow-up after completion of the primary studies. A subset of participants was evaluated for immunogenicity and safety of one or two additional doses administered 5–6 years after primary vaccination. Methods Participants were randomized to one additional dose (1-additional dose group, n=61), two additional doses (revaccination group, n=60), or no additional vaccination (control, n=119). Humoral and cell-mediated immunity were evaluated by anti-glycoprotein E (gE) antibodies, gE-specific CD4[2+] T-cells, and memory B-cells. Reactogenicity was evaluated for 7 days post-vaccination and overall safety was evaluated throughout the study. NCT02723773. Results Anti-gE geometric mean concentrations (GMCs) were 10,000–11,500 mIU/mL in all groups pre-additional vaccination. GMCs peaked at 1 month after one dose (73,834.4 and 79,419.8 mIU/mL in the 1-additional dose and revaccination groups, respectively), declined at Year 1, but remained above pre-additional vaccination levels thereafter. GMC was 64,603.0 mIU/mL 1 month after the second dose in the revaccination group. GMCs in the control group were 8825.4 mIU/mL at Year 1 and 6858.8 mIU/mL at Year 6. The frequency of gE-specific CD4[2+] T-cells and memory B-cells followed a similar pattern. Pain and fatigue were the most common solicited adverse events. No serious adverse events related to RZV were reported. Conclusions A single additional RZV dose elicited strong and durable humoral and cell-mediated anamnestic responses, with a reactogenicity and safety profile as established in primary studies.