Zoster vaccine associated with lower risk of shingles in older adults

"The pain of herpes zoster is often disabling and can last for months or even years, a complication termed postherpetic neuralgia. Approximately 1 million episodes of herpes zoster occur in the United States annually, but aside from age and immunosuppression, risk factors for this condition are not known," the authors write. Although prelicensure data provided evidence that herpes zoster vaccine works in a select study population under idealized circumstances, the vaccine needs to be evaluated in field conditions to show whether benefits of the vaccine can be generalized to conditions of clinical practice, according to background information in the article. The researchers note that this is particularly important for the herpes zoster vaccine, given the medical and physiological diversity in the elderly population for whom the vaccine is indicated.

Hung Fu Tseng, Ph.D., M.P.H., of Southern California Kaiser Permanente, Pasadena, Calif., and colleagues evaluated the risk of herpes zoster after receipt of herpes zoster vaccine among individuals in general practice settings. The study included community-dwelling adults, age 60 years or older, who were members of a managed care organization. There were 75,761 members in the vaccinated cohort, who were age matched (1:3) to 227,283 unvaccinated members.

Compared with the unvaccinated cohort, individuals in the vaccinated cohort were more likely to be white, women, and to have had more outpatient visits, and a lower prevalence of chronic diseases. There were 5,434 herpes zoster cases identified in the study (6.4 cases per 1,000 persons per year among vaccinated individuals and 13.0 cases per 1,000 persons per year among unvaccinated individuals). In the fully adjusted analysis, vaccination was associated with reduced risk of herpes zoster. The reduction in risk did not vary by age at vaccination, sex, race, or with presence of chronic diseases. Herpes zoster vaccine recipients had reduced risks of ophthalmic herpes zoster and hospitalizations coded as herpes zoster. Overall, the vaccine was associated with a 55 percent reduction in incidence of herpes zoster.

"Herpes zoster vaccine was licensed recently, which means the durability of its protection needs to be assessed in future studies. Meanwhile, however, this vaccine has the potential to annually prevent tens of thousands of cases of herpes zoster and postherpetic neuralgia nationally. To date, herpes zoster vaccine uptake has been poor due to weaknesses in the adult vaccine infrastructure and also due to serious barriers to the vaccine among clinicians and patients. Solutions to these challenges need to be found so that individuals seeking to receive herpes zoster vaccine will be able to reduce their risk of experiencing this serious condition," the authors conclude.