Loading...
Short-term follow-up of participants in placebo-controlled studies of the herpes zoster (HZ) vaccine confirmed that the vaccine was efficacious for at least 5 years (NEJM JW Gen Med Dec 1 2012 and Clin Infect Dis 2012; 55:1320). Now, long-term follow-up of some original vaccine recipients, including placebo-group members who were vaccinated when the studies were completed, has allowed investigators to estimate longer-term efficacy.
Almost 7000 vaccine recipients (median age, 74) were monitored for about 4 years after the original studies ended, most through year 10 after vaccination; of 347 suspected cases of HZ in this cohort, 263 were confirmed. Historical controls were used to assess several measures of vaccine efficacy. Efficacy against …