Routine vaccination against herpes zoster is effective against incident shingles in a general population of older individuals, including those who are immunosuppressed, as well as being effective against post-herpetic neuralgia, concludes a new study.
US researchers analysed the incidence of herpes zoster and post-herpetic neuralgia according to vaccination status in 766,330 randomly selected Medicare claimants aged 65 years or older, using administrative data for the period 1 January 2007 to 31 December 2009.
Overall uptake of the herpes zoster vaccine in the study population was low, at 3.9%. It was particularly low in black people (0.3%) and those with low income (0.6%). A total of 154 incident herpes zoster episodes occurred during 28,291 person-years of follow-up in the vaccinated group, compared with 12,958 incident events during 1,291,829 person-years of follow-up among unvaccinated participants, giving a zoster incidence of 5.4 per 1,000 person-years versus 10.0 per 1,000 person-years, respectively.
After adjusting for age, gender, race, immunosuppression, low income and comorbidity, the overall vaccine effectiveness against incident herpes zoster was 48%. Among immunosuppressed people the vaccine effectiveness against zoster was 37%. Vaccination was also associated with a reduction in post-herpetic neuralgia in people who experienced a shingles episode. At 30 days or longer after zoster, the vaccine effectiveness against post-herpetic neuralgia was 62% among vaccinees compared with those not vaccinated, while at 90 days or longer after shingles it was 59%.
What this means for GPs
Although the study was based on administrative data and vaccination was not randomised, the findings suggest routine shingles vaccination could significantly reduce the incidence of shingles and its long-term complication post-herpetic neuralgia in elderly populations. The researchers concluded: ‘As post-herpetic neuralgia is the major complication of herpes zoster and is associated with highly significant morbidity and adverse impacts on quality of life, substantial efforts are needed to increase vaccine use in routine care of elderly individuals.’