Herpes zoster vaccine and the incidence of recurrent herpes zoster in an immunocompetent elderly population.

ABSTRACT

BACKGROUND: The benefit of vaccinating immunocompetent patients who have had shingles has not been examined. The study assessed the association between vaccination and the incidence of herpes zoster recurrence among persons with a recent episode of clinically diagnosed herpes zoster. METHODS: This is a matched cohort study in Kaiser Permanente Southern California. Study populations were immunocompetent elderly individuals ≥ 60 years old with a recent episode of herpes zoster. Incidence of recurrent herpes zoster was compared between the vaccinated and the unvaccinated matched cohorts. RESULTS: A total of 1036 vaccinated and 5180 unvaccinated members were included. On the basis of clinically confirmed cases, the incidence of recurrent herpes zoster among persons aged <70 years was 0.99 (95% confidence interval [CI], .02-5.54) and 2.20 (95% CI, 1.10-3.93) cases per 1000 person-years in the vaccinated and unvaccinated cohorts, respectively. The adjusted hazard ratio was 0.39 (95% CI, .05-4.45) among persons aged <70 years and 1.05 (95% CI, .30-3.69) among persons aged ≥ 70 years. CONCLUSIONS: The risk of herpes zoster recurrence following a recent initial episode is fairly low among immunocompetent adults, regardless of vaccination status. Such a low risk suggests that one should evaluate the necessity of immediately vaccinating immunocompetent patients who had a recent herpes zoster episode.