Public health impact of herpes zoster vaccination on older adults in Singapore: a modeling study
Creators: name: Oh, Helen
name: Tan, Carol
name: Williams, Charles
name: Giannelos, Nikolaos
name: Ng, Cheryl
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Medicine
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Science Policy
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Computational Biology

description: In Singapore, population aging and rising life expectancy are increasing herpes zoster (HZ) burden, which may be reduced by vaccination. The present study modeled the public health impact of HZ vaccination in Singapore using ZOster ecoNomic Analysis (ZONA) model adapted with Singapore-specific key model inputs, where available. Base case analysis was conducted in adults ≥ 50 years of age (YOA), exploring three vaccination strategies (no vaccination, recombinant zoster vaccine [RZV], zoster vaccine live [ZVL]) under mass vaccination setting (30% coverage). Scenario and sensitivity analyses were performed. Out of 1.51 million adults in 2021 (base case population), 406,513 (27.0%) cases of HZ, 68,264 (4.5%) cases of post-herpetic neuralgia (PHN), and 54,949 (3.6%) cases of other complications were projected without vaccination. RZV was estimated to avoid 73,129 cases of HZ, 11,094 cases of PHN, and 9,205 cases of other complications over the subjects’ remaining lifetime; ZVL would avoid 17,565 cases of HZ, 2,781 cases of PHN, and 1,834 cases of other complications. The number needed to vaccinate to prevent one case of HZ/PHN was lower for RZV (7/41) than ZVL (26/163). Among all five age-stratified cohorts (50–59/60–64/65–69/70–79/≥80 YOA), RZV (versus no vaccination/ZVL) avoided the largest number of cases in the youngest cohort, 50–59 YOA. Results were robust under scenario and sensitivity analyses. Mass vaccination with RZV is expected to greatly reduce the public health burden of HZ among Singapore individuals ≥ 50 YOA. Findings support value assessment and decision-making regarding public health vaccination strategies for HZ prevention in Singapore. Risk of shingles (herpes zoster) increases with age, especially from 50 years. Shingles is a major public health concern in Singapore, given its rapidly aging population. Vaccination can prevent shingles and reduce its public health burden. Two shingles vaccines are available in Singapore: recombinant zoster vaccine (RZV) since 2021, zoster vaccine live (ZVL) since 2008. To understand the value of preventing shingles via vaccination, this study assessed the public health impact of shingles vaccination. Three vaccination strategies (no vaccination, vaccination with RZV, vaccination with ZVL) were compared in 1.51 million Singapore adults aged 50 years and above. Without vaccination, public health burden of shingles would be high; an estimated 406,513 (27.0%) would have shingles, 68,264 (4.5%) would have shingles-related long-term nerve pain, 54,949 (3.6%) would have other shingles-related complications, and 17,762 (1.2%) would be hospitalized due to shingles. Shingles vaccination could reduce this public health burden: RZV avoided 73,129 cases of shingles, 11,094 cases of shingles-related long-term nerve pain, 9,205 cases of other shingles-related complications, and 2,827 hospitalizations due to shingles, which was 4–6 times that avoided with ZVL (shingles: 17,565; shingles-related long-term nerve pain: 2,781; other shingles-related complications: 1,834; hospitalizations due to shingles: 484). Shingles vaccination for adults aged 50 years and above, especially early vaccination from 50–59 years, could reduce its public health burden more than vaccination at later ages and contribute toward healthy aging, preventive care, and the Healthier SG initiative. Results support local public health value assessments and decision-making for shingles prevention.