CDC recommends herpes zoster vaccine for people aged 60 years and older

Vaccine was associated with a 64% reduction of shingles in those aged 60 to 69 years.

Issue: June 2008

All people aged 60 years and older should receive the herpes zoster vaccine, according to recommendations from the Advisory Commitee on Immunization Practices.

The recommendations state that all adults aged 60 years and older should receive a single dose of the zoster vaccine (Zostavax, Merck) to prevent shingles. A 0.65 mL dose should be administered subcutaneously in the deltoid region, according to the recommendations. The vaccine should be administered to anyone without contraindications, including people who have had a prior episode of shingles.

The recommendations formalize provisional recommendations that were published in November 2006, after the herpes zoster vaccine was licensed by the FDA and recommended by the ACIP.

Efficacy studies of the herpes zoster vaccine demonstrated that the vaccine reduced the occurrence of shingles by 51.3% in people aged 60 years and older, according to findings summarized in a recent Morbidity and Mortality Weekly Report.

Research

Researchers conducted a phase-3, double blind, placebo-controlled trial to evaluate the efficacy of the herpes zoster vaccine in a study population of 38,546 healthy people aged 59 to 99 years. Individuals were randomly assigned to receive either a dose of the zoster vaccine or placebo.

Eligible participants had a history of varicella and at least 30 years of residence in the continental United States. The study group was followed up for incidence of zoster, incidence of postherpetic neuralgia, burden of illness and interference in activities of daily living.

Overall, the researchers found that the vaccine was effective against the severity of zoster rather than just prevention of the disease.

“Many consider the most feared consequence of herpes zoster to be postherpetic neuralgia,” Rafael Harpaz, MD, MPH, captain, U.S. Public Health Service, Division of Viral Diseases, National Center for Immunization and Respiratory Diseases/CDC, told Infectious Disease News. “Therfore, it is particularly notable that the zoster vaccine tends to be most effective at preventing the most severe episodes of postherpetic neuralgia.”

There were 315 confirmed cases of zoster among vaccine recipients and 642 cases among placebo recipients. The vaccine prevented postherpetic neuralgia in 66.5% of participants and had an independent effect of reduction by 39% in participants who developed zoster. The vaccine was effective in reducing burden of illness in 61.1% of participants.

Vaccine efficacy

The vaccine was most effective in preventing zoster in people aged 60 to 69 years. The vaccine was associated with a 64% reduction of shingles occurrences among this patient population. “This is possibly due to immune senescence,” Harpaz said. “However, the vaccine retained substantial efficacy against zoster in people older than 70 years old, with even better protection against postherpetic neuralgia in the older cohorts.”

The vaccine was 18% effective in preventing zoster in people aged 80 years and older.

“Prevention of zoster and its sequelae is particularly important among the oldest people because they experience the highest incidence of zoster and postherpetic neuralgia. In addition, they might be least able to seek medical attention for these conditions and to request treatment for ongoing pain. Furthermore, they might be least able to tolerate medications and procedures commonly used to treat postherpetic neuralgia, and they might have the least reserve to tolerate zoster and its complications. Finally, the oldest people are more likely to suffer social and psychological consequences from postherpetic neuralgia,” Harpaz said.

The efficacy of the vaccine against both zoster and postherpetic neuralgia declined during the first year after vaccination but leveled off through the remaining three years of follow-up.

The vaccine is considered to be cost-effective in comparison with other established public health interventions, according to researchers.

“This condition poses an enormous burden of disease in the United States, with about a million cases annually. In the past, the only tools we had to reduce that burden were the antivirals and other medications to reduce the duration and severity of the acute disease and postherpetic neuralgia. But these were only partially and inconsistently effective,” Harpaz said.

In a safety sub-study, there was a higher rate of serious adverse events in vaccine recipients vs. placebo recipients. However, the temporal and clinical patterns of these adverse events did not suggest that these were caused by the vaccine, according to the researchers. – by Rob Volansky

For more information:

Harpaz R, Ortega-Sanchez I, Seward J, et al. Prevention of herpes zoster: recommendations of the Advisory Committee on Immunization Practices. MMWR. 2008;57:1-30.

Oxman MN, Levin MJ, Johnson GR, et al. A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults. N Engl J Med. 2008;352:2271-2284.