While the effectiveness of live zoster vaccine against herpes zoster waned substantially following administration, some protection remained after 10 years in a real-world study, particularly against postherpetic neuralgia. The vaccine also reduced the risk of herpes zoster ophthalmicus and hospitalization for herpes zoster.
The investigators analyzed the medical records of more than 1.5 million people aged 50 years or older in Kaiser Permanente Northern California from 2007 through 2018. Outcomes included vaccine effectiveness in preventing herpes zoster, postherpetic neuralgia, herpes zoster ophthalmicus; admission to hospital for herpes zoster; and the change in vaccine effectiveness by time since vaccination. Live zoster vaccine is no longer available in the U.S. and many other countries, having been eclipsed by recombinant zoster vaccine.
“Of 1,505,647 people, 507,444 (34%) were vaccinated with live zoster vaccine,” the authors write. “Among 75,135 incident herpes zoster cases, 4,982 (7%) developed postherpetic neuralgia, 4,439 (6%) had herpes zoster ophthalmicus, and 556 (0.7%) were admitted to hospital for herpes zoster. For each outcome, vaccine effectiveness was highest in the first year after vaccination and decreased substantially over time. Against herpes zoster, vaccine effectiveness waned from 67% (95% confidence interval 65% to 69%) in the first year to 15% (5% to 24%) after 10 years. Against postherpetic neuralgia, vaccine effectiveness waned from 83% (78% to 87%) to 41% (17% to 59%) after 10 years. Against herpes zoster ophthalmicus, vaccine effectiveness waned from 71% (63% to 76%) to 29% (18% to 39%) during five to less than eight years. Against admission to hospital for herpes zoster, vaccine effectiveness waned from 90% (67% to 97%) to 53% (25% to 70%) during five to less than eight years. Across all follow-up time, overall vaccine effectiveness was 46% (45% to 47%) against herpes zoster, 62% (59% to 65%) against postherpetic neuralgia, 45% (40% to 49%) against herpes zoster ophthalmicus, and 66% (55% to 74%) against admission to hospital for herpes zoster.”