A large real-world study confirms its efficacy.

The recombinant zoster vaccine (Shingrix) was approved in 2017 in the USA on the basis of its near-100% efficacy in clinical trials (NEJM JW Infect Dis Jun 2015 and N Engl J Med 2015; 372: 2087-2096; NEJM JW Gen Med Oct 15 2016 and N Engl J Med 2016; 375: 1019-1032). Enough time has passed now to examine its efficacy in clinical use.

In a prospective US Centers for Disease Control and Prevention-funded cohort study, researchers followed almost two million adults (age, 50 years and over) who were receiving care in one of several large US healthcare systems. About 40% were older than 65 years. After five years, almost 50% of those who were still enrolled in the study had received at least one dose of recombinant zoster vaccine, and 38% had received the recommended two doses.

Overall incidence of zoster (defined as the presence of the specific diagnostic code in the medical record, accompanied by a prescription for acyclovir) was lower among vaccine recipients, with vaccine protective efficacy estimated to be 64% after a single dose and 76% after two doses. The efficacy of the two-dose regimen was unchanged even if the interval between doses was greater than the recommended six months; it waned very little during follow up. Subgroup analyses confirmed efficacy in all age groups, as well as among people who had received the live zoster vaccine previously and in those who were taking corticosteroids at the time of vaccination.

Comment: This study echoes the results of several recent observational studies and confirms that recombinant zoster vaccine performs in the real world pretty much as promised. The clinical endpoint used here (chart diagnosis of zoster plus antiviral drug prescription) is less exact than the polymerase chain reaction-based endpoint in the licensing trials and might account for the somewhat lower efficacy noted in this study.

Abigail Zuger, MD, Former Associate Clinical Professor of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai; former Senior Attending Physician, Mount Sinai Roosevelt and Mount Sinai St. Luke’s Hospitals, New York City, USA.

Zerbo O, et al. Effectiveness of recombinant zoster vaccine against herpes zoster in a real-world setting. Ann Intern Med 2024 Jan 9; e-pub (https://doi.org/10.7326/M23-2023).

This summary is taken from the following Journal Watch titles: General Medicine, Neurology, Infectious Diseases, Ambulatory Medicine.