Shingles Vaccine: Effective and Costly or Cost-Effective?

The epidemiology and clinical impact of the varicella- zoster virus (VZV) changed dramatically with the introduction in 1995 of the varicella vaccine, after which the incidence of varicella in children plummeted (1). Nevertheless, the entire adult U.S. population remains at risk for shingles, a late complication of earlier varicella infection, and that risk is likely to increase as the baby boom generation ages and life expectancy increases. Shingles is characterized by a painful vesicular eruption in a dermatomal distribution and is caused by the reactivation of latent VZV in sensory ganglia. Approximately 25% of the U.S. population will have a shingles episode during their lifetime. Risk for occurrence is greatest in immunosuppressed persons and elderly persons, with the increased risk accelerating from 50 years of age. Among patients with shingles, 10% to 33% develop postherpetic neuralgia (PHN), a chronic and often severely painful condition with no effective treatment. The risk for PHN after shingles increases with age, especially after 60 years of age (2).

Fortunately, a new vaccine (Zostavax, Merck & Co., Whitehouse Station, New Jersey) specifically targets shingles. This vaccine was evaluated in a major phase III trial that involved 38 546 persons 60 years of age or older (3). The vaccine reduced the risk for shingles and PHN by 51% and 67%, respectively, suggesting added benefits to persons who develop shingles despite being vaccinated. The efficacy against shingles decreased with the age of the person vaccinated to 18% for persons …