Positive findings from the phase 3 trial ZOSTER-049 (NCT02723773) have revealed that the recombinant zoster vaccine (RZV, Shingrix; GlaxoSmithKline) maintains its efficacy against shingles for more than a decade in adult patients aged over 50 years. The trial, which constitutes a long-term follow-up, monitored enrolled patients for approximately 11 years following their initial vaccination.
RZV is a non-live, recombinant subunit vaccine designed for the prevention of shingles in adults aged 50 years and older. Combining glycoprotein E, an antigen, with AS01B, an adjuvant system, the vaccine aims to bolster immune responses in this age group, countering the natural decline in immunization responses that contributes to susceptibility to shingles. RZV is also recommended for individuals aged 18 years and older at increased risk for shingles but is not intended to prevent primary varicella infection, commonly known as chickenpox.
The ZOSTER-049 trial, also known as ZOE-LTFU, represents a long-term follow-up to the previous randomized phase 3 trials, ZOSTER-006 and ZOSTER-022 (also referred to as ZOE-50 and ZOE-70, respectively). More than 7,541 participants aged 50 and older from the preceding phase 3 trials were enrolled in the current trial. The safety, efficacy, and immunogenicity of the RZV vaccine were assessed at the time of vaccination and for an additional 6 years after patients completed the ZOSTER-006 and ZOSTER-022 trials, with observation continuing for up to 11 years.
According to trial results, RZV demonstrated a vaccine efficacy (VE) of 79.7% in patients aged 50 years and older over the 6- to 11-year period post-vaccination (95% CI 73.7–84.6). Positive outcomes were also observed in adults aged 70 years and older, with a VE of 73.1% within the same timeframe (95% CI 62.9–80.9), indicating high efficacy across both age groups. Additionally, at the 11-year mark, an 82% VE was observed in adults (95% CI 63.0–92.2), with VE remaining consistently high in subsequent years following initial vaccination.
Javier Díez-Domingo, PhD, principal investigator at the Foundation for the Promotion of Health and Biomedical Research of the Valencian Community, Spain, stated in a press release, “These final data demonstrate continued protection over more than a decade with high efficacy maintained in both the 50 plus and 70 plus age groups. Infectious diseases like shingles pose a significant risk to adults due to the natural decline in our immune system, and these data represent a remarkable advancement in our understanding of what can be achieved long-term for effective protection against shingles.”
Investigators reported no new safety concerns during the trial, with no serious adverse events (AEs) deemed related to RZV vaccination. The most commonly reported AEs among patients who received the RZV vaccine included pain at the injection site, myalgia, fatigue, and headache. However, most of these occurrences were mild to moderate in intensity and lasted less than 3 days. The study data are scheduled to be presented at the European Society of Clinical Microbiology and Infectious Diseases Global Congress in Barcelona, Spain, from April 27 to April 30, 2024.
Phil Dormitzer, senior vice president and Head of Vaccines R&D, remarked, “These data go far beyond the typical long-term follow-up period for a trial, tracking the efficacy of vaccination for some participants as they aged into their 70s, 80s, and 90s. With the vaccine now included in many national immunization programs around the world, these data add to the body of evidence on the extended long-term protection against shingles and provide further confidence to inform public immunization strategies.”
