ESTIMATING THE IMPACT OF UNIVERSAL VARICELLA VACCINATION IN JORDAN
Author(s)
Daniels V1, Hayajneh WA2, Weiss TJ3, Pillsbury M3, Kyle J1, Wolfson LJ3
1Atlas Data Systems, Berkeley Heights, NJ, USA, 2Jordan University of Science and Technology, Irbid, Jordan, 3Merck & Co., Inc., Kenilworth, NJ, USA
OBJECTIVES: More than 50% of the Levant population has access to universal varicella vaccination (UVV). In order to avoid changes in the age-distribution of varicella cases, and significantly reduce disease burden, it is important for other countries in the region to consider UVV. The objective of this study is to assess the magnitude of current varicella disease burden and the potential impact of UVV in Jordan. METHODS: A dynamic transmission model of varicella infection was calibrated to available varicella seroprevalence data within the region and validated against local epidemiological data. The current burden was assessed by converting the calibration into age-specific incidence and mortality rates, and the impact of one-dose UVV administered at 12 months of age with 90% coverage (concurrent with MMR vaccination which as >95% coverage) was estimated. Alternative vaccination strategies were examined as sensitivity analyses. RESULTS: The model estimates the current burden of varicella to be 188,000 cases per year, an incidence rate of 2,475/100,000 persons. Varicella incidence is projected to decrease by 38% at 1 year, 79% at 5 years, 86% at 10 years, and 90% at 25 years. After 5 years of UVV, 743,000 cases and 93 deaths due to varicella will be prevented; over a 25 year period, more than 4 million cases and 500 deaths due to varicella will be prevented. Importantly, the public health benefits extend beyond vaccinees, with a 92% disease reduction in unvaccinated infants and an 84% reduction in unvaccinated adults. At low coverage levels (10%), such as might be seen with private-sector only varicella vaccination, slight shifts in the age-distribution of cases to older adults are likely. CONCLUSIONS: UVV in Jordan will significantly reduce varicella disease burden and protect against possible age-shifts in varicella case distribution that could be caused by synergies of private-sector only vaccination and high UVV rates within the region.
Conference/Value in Health Info
2017-05, ISPOR 2017, Boston, MA, USA
Value in Health, Vol. 20, No. 5 (May 2017)
Code
PIN82
Topic
Epidemiology & Public Health
Topic Subcategory
Public Health
Disease
Infectious Disease (non-vaccine), Pediatrics, Sensory System Disorders