Two doses of recombinant zoster vaccine (RZV) are effective against herpes zoster (HZ), with the vaccine effectiveness (VE) of two doses waning little over four years of follow-up, according to a study published in the Annals of Internal Medicine.
Ousseny Zerbo, Ph.D., from Kaiser Permanente Northern California in Oakland, and colleagues conducted a prospective cohort study involving persons aged 50 years or older to evaluate the real-world effectiveness of RZV against HZ. The study included close to 2.0 million persons aged 50 years or older from four health care systems in the Vaccine Safety Datalink, with 7.6 million person-years of follow-up.
The researchers found that after adjustment, VE was 64 and 76 percent for one and two doses, respectively. After one dose only, VE was 70, 45, 48, and 52 percent during the first year, second year, third year, and after the third year, respectively. After two doses, VE was 79, 75, and 73 percent during the first, second, and third and fourth years, respectively. VE was 65 and 77 percent in those who received and did not receive corticosteroids before vaccination, respectively.
“Our finding of substantial VE among corticosteroid recipients underscores the value of vaccination for these persons, who are at increased risk for HZ,” the authors write. “Our finding that the effectiveness of one dose decreased after a year further supports the current recommendation for a second dose.”