PNEUMOCOCCAL VACCINATION STRATEGIES IN OLDER ADULTS IN VIETNAM ACCOUNTING FOR CHILDHOOD VACCINATION EFFECTS: A COST-EFFECTIVENESS ANALYSIS USING A DYNAMIC TRANSMISSION MODEL
Author(s)
Khuong Ba Cao, MD1, Arnold Hagens, MD1, Due The Ong, PhD2, Lan Nguyen Thi Phuong, PhD3, Maarten Postma, PhD4, Jurjen van der Schans, PhD5.
1UMCG, University of Groningen, Groningen, Netherlands, 2Health Strategy and Policy Institute, Ministry of Health, Hanoi, Viet Nam, 3Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen, Viet Nam, 4University of Groningen, Groningen, Netherlands, 5UMCG/Health Ecore, Groningen, Netherlands.
1UMCG, University of Groningen, Groningen, Netherlands, 2Health Strategy and Policy Institute, Ministry of Health, Hanoi, Viet Nam, 3Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen, Viet Nam, 4University of Groningen, Groningen, Netherlands, 5UMCG/Health Ecore, Groningen, Netherlands.
OBJECTIVES: This study aimed to evaluate the cost-effectiveness of adult pneumococcal vaccination strategies, including PCV20, PCV21, PPSV23, sequential PCV13/PPSV23, and PCV15/PPSV23, compared with no adult vaccination.
METHODS: A deterministic dynamic transmission model was adapted to evaluate the cost-effectiveness of adult pneumococcal vaccination strategies in Vietnam, incorporating indirect effects (herd immunity and serotype replacements) from PCV13 EPI. The transmission model included six age groups, eleven serotype classes and transmission dynamics, including carriage acquisition, clearance, and competition among co-circulating serotypes. Analyses were conducted from a societal perspective over a lifetime horizon, with outcomes reported as costs per case averted and per quality-adjusted life year (QALY) gained.
RESULTS: Over a 100-year horizon, the greatest health impact was observed with sequential PCV13/PPSV23 and PCV15/PPSV23 strategies, averting 16970 invasive pneumococcal disease cases, 679070 community-acquired pneumonia cases, and 55417 acute otitis media cases, with 72878 QALYs gained versus the reference. PCV20, PCV21, and PPSV23 elderly strategies averted 68465, 62 276, and 41693 QALYs, respectively. Total discounted costs ranged from USD 2.89 bilion (PPSV23) to USD 6.41 billion (PCV21), compared with USD 2.10 bilion for PCV13 EPI alone. Incremental cost-effectiveness ratios versus PCV13 EPI ranged from USD 31506/QALY for PCV13/PPSV23 to USD 140773/QALY for PCV21, all substantially exceeding Vietnam’s willingness-to-pay threshold of 3xGDP (USD 12900/QALY). Probabilistic sensitivity analysis confirmed these findings, with probabilities of cost-effectiveness at the 3xGDP threshold ranging from 1.0% to 9.3%; the highest probability was observed for PCV13/PPSV23. Overall, none of the evaluated adult vaccination strategies were cost-effective relative to no adult vaccination while considering the impacts of PCV13 EPI.
CONCLUSIONS: Although adult pneumococcal vaccination strategies reduced disease burden and improved health outcomes compared to no adult vaccination while considering the impacts of childhood programe, the evaluated strategies exceeded Vietnam’s cost-effectiveness thresholds and had a low probability of being cost-effective under current assumptions.
METHODS: A deterministic dynamic transmission model was adapted to evaluate the cost-effectiveness of adult pneumococcal vaccination strategies in Vietnam, incorporating indirect effects (herd immunity and serotype replacements) from PCV13 EPI. The transmission model included six age groups, eleven serotype classes and transmission dynamics, including carriage acquisition, clearance, and competition among co-circulating serotypes. Analyses were conducted from a societal perspective over a lifetime horizon, with outcomes reported as costs per case averted and per quality-adjusted life year (QALY) gained.
RESULTS: Over a 100-year horizon, the greatest health impact was observed with sequential PCV13/PPSV23 and PCV15/PPSV23 strategies, averting 16970 invasive pneumococcal disease cases, 679070 community-acquired pneumonia cases, and 55417 acute otitis media cases, with 72878 QALYs gained versus the reference. PCV20, PCV21, and PPSV23 elderly strategies averted 68465, 62 276, and 41693 QALYs, respectively. Total discounted costs ranged from USD 2.89 bilion (PPSV23) to USD 6.41 billion (PCV21), compared with USD 2.10 bilion for PCV13 EPI alone. Incremental cost-effectiveness ratios versus PCV13 EPI ranged from USD 31506/QALY for PCV13/PPSV23 to USD 140773/QALY for PCV21, all substantially exceeding Vietnam’s willingness-to-pay threshold of 3xGDP (USD 12900/QALY). Probabilistic sensitivity analysis confirmed these findings, with probabilities of cost-effectiveness at the 3xGDP threshold ranging from 1.0% to 9.3%; the highest probability was observed for PCV13/PPSV23. Overall, none of the evaluated adult vaccination strategies were cost-effective relative to no adult vaccination while considering the impacts of PCV13 EPI.
CONCLUSIONS: Although adult pneumococcal vaccination strategies reduced disease burden and improved health outcomes compared to no adult vaccination while considering the impacts of childhood programe, the evaluated strategies exceeded Vietnam’s cost-effectiveness thresholds and had a low probability of being cost-effective under current assumptions.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EE289
Topic
Economic Evaluation, Epidemiology & Public Health, Health Technology Assessment
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, Vaccines