The adjuvanted recombinant zoster vaccine is efficacious and safe in Asian adults ≥ 50 years of age: a sub-cohort analysis of the ZOE-50 and ZOE-70 randomized trials

Real-world effectiveness of recombinant zoster vaccine in self-identified Chinese individuals aged ≥50 years in the United States

We evaluated the vaccine effectiveness (VE) of two doses of recombinant zoster vaccine (RZV) against herpes zoster (HZ) and postherpetic neuralgia (PHN) in Chinese adults at Kaiser Permanente Southern California (KPSC). Chinese KPSC members were identified based on self-reported ethnicity or self-reported preferred spoken/written language. Those aged ≥50 years who received two doses of RZV 4 weeks to ≤ 6 months apart were matched 1:4 to RZV unvaccinated Chinese members and followed through June 2022; second doses were accrued 6/1/2018-12/31/2020. We estimated incidence and adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) comparing outcomes (HZ and PHN). Adjusted VE (%) was calculated as (1-aHR)×100. 3978 RZV vaccinated Chinese members were matched to 15,912 RZV unvaccinated Chinese members. The incidence per 1000 person-years (95% CI) of HZ in the vaccinated group was 1.5 (0.9-2.5) and 10.9 (9.8-12.1) in the unvaccinated group; aHR (95% CI) was 0.12 (0.07-0.21). Adjusted VE (95% CI) was 87.6% (78.9-92.7) against HZ. We identified 0 PHN cases in the vaccinated group and 19 in the unvaccinated group. Among Chinese adults aged ≥50 years, two doses of RZV provided substantial protection against HZ and PHN supporting the real-world effectiveness of the vaccine in this population.

Public health impact of herpes zoster vaccination on older adults in Hong Kong

The growing burden of herpes zoster (HZ) in Hong Kong, due to an aging population with increasing life expectancy, may be reduced by vaccination. This study aimed to estimate public health impact of HZ vaccination in Hong Kong. The ZOster ecoNomic Analysis (ZONA) model was adapted with Hong Kong-specific key model inputs/assumptions, where available. Base case analysis involved adults ≥50 years of age (YOA), exploring three vaccination strategies (no vaccination/recombinant zoster vaccine [RZV]/zoster vaccine live [ZVL]) under private market (5% coverage) and mass vaccination (40% coverage) settings. Scenario and sensitivity analyses were performed. In the base case population (3.13 million), without vaccination, 891,024 HZ (28.4%), 156,097 post-herpetic neuralgia (PHN) (5.0%), and 38,755 (1.2%) HZ ophthalmicus (HZO) were projected over their remaining lifetime. Mass RZV vaccination reduced HZ, PHN, and HZO cases by 204,875 (-23.0%), 31,949 (-20.5%), and 8,471 (-21.9%), respectively, which was 4-5 times that reduced with ZVL. RZV was more efficient than ZVL, with lower number needed to vaccinate to prevent one HZ/PHN/HZO case (RZV: 7/40/148; ZVL: 27/163/709). Among all age cohorts, the greatest reduction in cases was projected for RZV (versus no vaccination/ZVL) in the youngest cohort, 50-59 YOA. Results were robust under scenario and sensitivity analyses. HZ burden in Hong Kong is substantial. Mass RZV vaccination is expected to considerably reduce public health burden of HZ among individuals ≥50 YOA, compared with no vaccination/ZVL. Results may support value assessment and decision-making regarding vaccination strategies for HZ prevention in Hong Kong.

Healthy ageing: Herpes zoster infection and the role of zoster vaccination

Populations are ageing worldwide, with considerable time lived in ill-health, putting upwards pressure on healthcare budgets. Healthy ageing is defined as maintaining functional ability, including the ability to: meet basic needs; learn, grow and make decisions; be mobile; build and maintain relationships; and contribute to society. The risk and impact of infectious diseases increase with age due to immunosenescence. Vaccination can help to prevent disease in older adults, promoting healthy ageing and active lives. Herpes zoster (HZ) occurs when the varicella zoster virus is reactivated due to declining immunity. HZ is common, with a lifetime risk of one-third, and increases in incidence with age. HZ is associated with severe and intense pain, substantially affecting the functional status of patients as well as their overall health-related quality of life. HZ and its complications may result in prolonged morbidity, including persistent pain (post-herpetic neuralgia, PHN), hearing impairment, vision loss and increased risk of stroke and myocardial infarction. HZ and PHN are difficult to treat, substantiating the benefits of prevention. Vaccines to prevent HZ include a recombinant zoster vaccine (RZV). RZV has shown efficacy against the HZ burden of disease and HZ burden of interference on activities of daily living of over 90% in immunocompetent adults aged ≥50 years. Vaccine efficacy against HZ was maintained at over 70% at 10 years post-vaccination. Adult vaccination, including against HZ, has the potential to reduce burden of disease, thus helping to maintain functioning and quality of life to support healthy ageing in older adults.

Safety and reactogenicity of the adjuvanted recombinant zoster vaccine: experience from clinical trials and post-marketing surveillance

An adjuvanted recombinant zoster vaccine (RZV) is licensed for the prevention of herpes zoster. This paper reviews its safety and reactogenicity. A pooled analysis of two pivotal randomized Phase-3 trials (NCT01165177, NCT01165229) in adults ⩾50 years found that more solicited adverse events (AEs) were reported with RZV than placebo. Injection site pain was the most common solicited AE (RZV: 78.0% participants; placebo: 10.9%). Grade-3 pain occurred in 6.4% of RZV and 0.3% of placebo recipients. Myalgia, fatigue, and headache were the most commonly reported general solicited AEs (RZV: 44.7%, 44.5%, and 37.7%, respectively; placebo: 11.7%, 16.5%, and 15.5%, respectively). Most symptoms were mild to moderate in intensity with a median duration of 2–3 days. The intensity of reactogenicity symptoms did not differ substantially after the first and second vaccine doses. The pooled analysis of the pivotal Phase-3 trials did not identify any clinically relevant differences in the overall incidence of serious adverse events (SAEs), fatal AEs or potential immune-mediated diseases (pIMDs) between RZV and placebo. Reactogenicity in five studies of immunocompromised patients ⩾18 years (autologous stem cell transplant, human immunodeficiency virus, solid tumors, hematological malignancies, and renal transplant; NCT01610414, NCT01165203, NCT01798056, NCT01767467, and NCT02058589) was consistent with that observed in the pivotal Phase-3 trials. There were no clinically relevant differences between RZV and placebo in the immunocompromised populations with regard to overall incidence of SAEs, fatal AEs, pIMDs, or AEs related to patients’ underlying condition. Post-marketing surveillance found that the most commonly reported AEs were consistent with the reactogenicity profile of the vaccine in clinical trials. Overall, the clinical safety data for RZV are reassuring.

Effectiveness of the recombinant zoster vaccine among Kaiser Permanente Hawaii enrollees aged 50 and older: A retrospective cohort study

BACKGROUND

The incidence of herpes zoster (HZ) has been on the rise for decades in the United States. Clinical trials for the recombinant zoster vaccine (RZV) demonstrated vaccine efficacy of over 90% in preventing herpes zoster. However, there is limited information on its effectiveness outside of a clinical trial setting, as well as its effectiveness against herpes zoster ophthalmicus (HZO).

METHODS

A de-identified electronic health records database from Kaiser Permanente Hawaii (KPH) was used to conduct this retrospective cohort study to assess the effectiveness of the recombinant zoster vaccine against HZ and HZO in immunocompetent, vaccine age-eligible individuals without a prior history of HZ, who were continuously enrolled in KPH for ≥365 days prior to becoming age-eligible for RZV between January 1, 2018, through December 31, 2019.

RESULTS

A total of 78 356 adults were included in this study, with 11 864 (15.1%) adults receiving two valid doses of the recombinant zoster vaccine. The incidence rate of HZ was 325.6 (95% CI: 217.7 to 464.4) cases per 100 000 person-years in vaccinated persons compared to 1063.3 cases per 100 000 person-years (95% CI: 1006.0 to 1122.8) in the unvaccinated group. The incidence rate of HZO was 11.9 (95% CI: 0.7 to 52.3) cases per 100 000 person-years in the vaccinated group compared to 72.1 (95% CI: 58.0 to 88.3) in the unvaccinated group. RZV was 83.5% (95% CI: 74.9% to 89.2%) effective against HZ and 93.3% (95% CI: 48.7% to 99.1%) effective against HZO.

CONCLUSIONS

RZV has demonstrated high effectiveness against both HZ and HZO outside of a clinical trial setting in the United States. Vaccine coverage is low, emphasizing the need for public health efforts to increase vaccination to reduce morbidity from HZ and HZO.