Safety, tolerability, and immunogenicity after 1 and 2 doses of zoster vaccine in healthy adults ≥60 years of age

Immunogenicity and safety of a live attenuated shingles (herpes zoster) vaccine (Zostavax®) in individuals aged ≥ 70 years: A randomized study of a single dose vs. two different two-dose schedules

“…Conversely, in the 3-mo schedule, the post-dose 2/post-dose 1 GMT ratio and 95% CIs were < 1. These results are consistent with the study performed by Vermeulen et al 33 where participants had a similar level of antibodies after each dose given 6 weeks apart. These results seem to indicate a lower post-dose 2 response when increasing the interval between doses from 1 to 3 mo.…”

“…33 The geometric mean-fold rise (GMFR) in VZV antibodies measured using gpELISA was lower in that study than in the present study: 1.6 (95% CI 1.4-1.8) after the first dose, and 1.5 (95% CI 1.3-1.7) after the second dose; 33 the difference could be related to the difference in vaccination schedule (0 and 6 weeks) and assessment of immune response 6 weeks after each dose, as opposed to 4 weeks in the current study. Table 3.…”

“…32 In a randomized, placebo-controlled study, two doses of Zostavax were given 6 weeks apart to individuals aged ≥ 60 y. VZV-specific CMI response, measured 6 weeks post-dose, was similar for both doses. 33 The second dose was generally well tolerated but did not boost VZVspecific immunity beyond levels achieved after dose 1. Therefore, there was no apparent immunological advantage of administering a second dose of HZ vaccine 6 weeks after an initial dose.…”

Background paper to the decision not to recommend a standard vaccination with the live attenuated herpes zoster vaccine for the elderly in Germany

“…A total of 5 RCTs were included to assess the safety of the live HZ vaccine [36,37,[42][43][44][45]. They vary widely with regard to their consideration of the relevant endpoints and participant numbers.…”

Varicella and herpes zoster vaccine development: lessons learned

“…There remains debate about the extent to which VZV-specific antibody titers can predict protection against zoster, which is largely cell mediated [5]. Nevertheless, two-dose vaccination strategies (compared to the current single-dose regimen), with doses separated by up to 12 months, seem to show little promise; there is no difference between the VZV antibody responses 4 weeks after the first or second dose [111,112]. However, a booster dose has potential to reverse this decline in protection.…”