RZV lowers herpes zoster risk in older adults

The use of a recombinant zoster vaccine (RZV) significantly lowers the risk of developing herpes zoster in older adults aged ≥65 years compared with placebo, according to a study presented at WONCA 2024.

“The risk of herpes zoster is strongly associated with increasing age. Herpes zoster can cause a painful dermatomal rash, with sequelae including post-herpetic neuralgia and potentially life-threatening complications,” according to the researchers.

To assess the clinical effectiveness of RZV against herpes zoster, using data from the TriNetX Research Network, the researchers conducted a retrospective cohort study involving 192,456 individuals aged ≥65 years who received a two-dose RZV compared with those who did not (n=96,228 in each group).

Results showed that individuals vaccinated with RZV were significantly less likely to develop herpes zoster, the primary endpoint of the study, than those unvaccinated (n=801 vs 1,638; hazard ratio [HR], 0.48, 95 percent confidence interval [CI], 0.44–0.52; p<0.01). [WONCA 2024, abstract 533]

For secondary endpoints, vaccinated individuals demonstrated significantly lower risk of severe herpes zoster, including neurologic complications (eg, encephalitis, meningitis, ocular disease, or disseminated zoster) compared with the unvaccinated (n=125 vs 336; HR, 0.37; 95 percent CI, 0.30–0.45; p<0.01).

There was also a significant reduction in the risk of nonsevere herpes zoster in the vaccinated group compared with the unvaccinated group (n=727 vs 1,502; HR, 0.48; 95 percent CI, 0.44–0.52; p<0.01).

In addition, across all subgroups, the vaccinated cohort had a consistently lower risk of herpes zoster than the unvaccinated cohort, regardless of age (HRs, 0.63 [65–74 years] and 0.78 [≥75 years]; p<0.01 for both) and sex (HRs, 0.56 [male] and 0.81 [female]; p<0.01 for both).

“Taken together, RZV has demonstrated effectiveness against severe and nonsevere herpes zoster in individuals aged ≥65 years. The findings of this study support clinicians in recommending the use of the recombinant zoster vaccine for the elderly population,” noted the researchers.

This result was consistent with an earlier study, which showed that two-dose RZV vaccination was effective in preventing herpes zoster in Chinese adults aged ≥50 years (vaccine effectiveness of 87.6 percent). Thus, it supports the recommendation of RZV vaccination for adults aged ≥50 years. However, the researchers noted that further studies with longer follow-up periods are still warranted to evaluate the durability of RZV. [Hum Vaccin Immunother 2024;20:2327145]

RZV is the first herpes zoster vaccine approved for use in immunocompromised persons. With moderate-to-high vaccine efficacy and an acceptable safety profile, RZV has the potential to prevent considerable herpes zoster incidences and related complications. [www.cdc.gov/mmwr/volumes/71/wr/pdfs/mm7103a2-H.pdf]

RZV was approved for the prevention of herpes zoster, or shingles, in adults aged ≥50 years by the FDA* and for immunocompetent adults aged ≥50 years by the ACIP** in 2017. [www.cdc.gov/shingles/hcp/vaccine-considerations/immunocompromised-adults.html]