Herpes zoster vaccine lowered shingles incidence among the elderly, regardless of age, race or the presence of chronic disease, results of a retrospective cohort study revealed.
Although results from clinical trials indicated that the herpes zoster vaccine (Zostavax; Merck) reduced herpes zoster (50%; P<.001) and postherpetic neuralgia (P<.001) incidence in those aged 60 and older (n=38,646), this is the first trial to confirm these results in clinical practice.
“This is particularly important for herpes zoster vaccine, given the medical and physiological diversity in the elderly population for whom the vaccine is indicated and since there are stringent storage and handling requirements for this live-attenuated vaccine,” study researcher Hung Fu Tseng, PhD, MPH, and colleagues from Kaiser Permanente Southern California, wrote in the Journal of the American Medical Association.
Tseng and colleagues retrospectively analyzed the incidence of herpes zoster from January 1, 2007 to December 31, 2009 in individuals enrolled in the Kaiser Permanente health plan. They age matched 75,761 vaccinated patients to 227,283 unvaccinated patients. There were a total of 5,434 shingles cases during the study period.
Herpes zoster incidence was 6.4 per 1,000 person years among vaccinated individuals (95% CI: 5.9-6.8) compared with 13 per 1,000 person years among unvaccinated individuals (95% CI: 12.6-13.3; HR=0.45, 95% CI:0.42-0.48). This equates to one fewer shingles episode for every 71 individuals vaccinated, according to the researchers.
Because this lower herpes zoster risk was retained across all age strata (P=.62), the researchers encouraged offering herpes zoster to “eligible patients of all ages including the oldest populations.”
“[T]his could translate into a very large absolute reduction in disease because they bear the greatest burden of herpes zoster and postherpetic neuralgia and are also especially vulnerable to these disabling conditions,” the researchers wrote.
CDC estimates from the 2009 National Health Interview Survey indicate that herpes zoster vaccine uptake is still low — only 10.9% of those aged 60 and older reported receiving the vaccine.
Financial reasons were the most frequently sited barrier to herpes zoster vaccine administration in a survey of general internists and family medicine physicians published in the May 2010 Annals of Internal Medicine. Other findings indicated that only 45% of respondents knew the vaccine was reimbursable through Medicare Part D.
“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 researchers wrote.
Because the vaccine was licensed only recently, they noted that more research is still needed to determine long-term durations of protection.