Knowledge, attitude, and practice toward herpes zoster (HZ) and HZ vaccination: Concept elicitation findings from a multi-country study in the Asia Pacific.

Herpes zoster (HZ) is a prevalent disease characterized by a painful rash. A multi­country study was conducted to elicit public and physician knowledge, attitude, and practice (KAP) toward HZ disease and vaccination for the assessment of local factors influencing HZ vaccine perceptions in four Asian-Pacific countries/territories One-to-one qualitative interviews were conducted in 2022, among the public (people aged ≥ 50 years, adults with parents aged ≥ 50 years, zoster vaccine live-vaccinated individuals aged ≥ 50 years in Republic of Korea, and HZ patients; n = 78) and physicians (general practitioners and specialists; n = 24). Themes surrounding KAP toward HZ and HZ vaccination were summarized using a thematic analysis. A substantial knowledge gap related to HZ was observed among the public, including its causes, long-term impacts, and the at-risk population. There was a low perceived risk of HZ and low general awareness of HZ vaccine availability, although country/territory-specific differences existed. Fear of HZ-associated pain contributed toward vaccination intent among HZ patients and adults with parents aged ≥ 50 years. HZ-naïve adults who were encouraged to receive the vaccine by others were not motivated to do so due to optimism bias. Physicians were perceived to be a reliable source of information. However, physicians did not always proactively discuss HZ vaccination due to time constraints and a perceived need to prioritize other vaccinations including influenza and pneumococcal vaccines. Initiatives are needed to improve public awareness of HZ and its complications, in terms of overall impact on individuals and society, and highlight the important role of physicians in recommending vaccination.

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.

In Hong Kong, the burden of shingles is increasing due to an aging population with increasing life expectancy. Vaccination can prevent shingles and reduce disease burden. Since 2021, two shingles vaccines are available in Hong Kong: zoster vaccine live (ZVL) and recombinant zoster vaccine (RZV). Using mathematical modeling, this study compared the public health impact (the number of cases of disease that would occur) of different shingles vaccination strategies, in a hypothetical population of 3.13 million Hong Kong adults aged ≥50 years in their remaining lifetime. The three strategies compared were no vaccination versus vaccination with ZVL or RZV. With no vaccination, public health burden of shingles would remain high, where an estimated 2 in 7 will have shingles, 1 in 20 will have shingles-related nerve pain, and 1 in 100 will have shingles around the eye. Vaccination (versus no vaccination) was predicted to reduce these cases by 47,477 (shingles), 7,701 (nerve pain), and 1,769 (shingles around the eye) for ZVL; and 204,875 (shingles), 31,949 (nerve pain), and 8,471 (shingles around the eye) for RZV. RZV avoided 4­5 times the number of cases compared with ZVL. Earlier RZV vaccination, from age 50 years, would have a greater public health impact than vaccination at a later age as the percentage of cases avoided with RZV (versus no vaccination) was highest in people aged 50­59 years compared with other age groups. These results may support value assessment and decision-making on public health vaccination strategies for shingles prevention in Hong Kong.