Cost-Effectiveness Analysis for Influenza Vaccination Coverage and Timing in Tropical and Subtropical Climate Settings: A Modeling Study

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Value Health. 2019 Dec;22(12):1345-1354. doi: 10.1016/j.jval.2019.07.001. Epub 2019 Aug 19. Cost-Effectiveness Analysis for Influenza Vaccination Coverage and Timing in Tropical and Subtropical Climate Settings: A Modeling Study.

Yue M¹, Dickens BL², Yoong JS³, I-Cheng Chen M², Teerawattananon Y⁴, Cook AR⁵.
Author information

1 School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, China; Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore. 2 Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore. 3 Center for Economic and Social Research, University of Southern California, Los Angeles, CA, USA; Yong Loo Lin School of Medicine, National University of Singapore, Singapore. 4 Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore; Health Intervention and Technology Assessment Program, Ministry of Public Health, Nonthaburi, Thailand. 5 Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore; Program in Health Services and Systems Research, Duke-NUS Medical School, Singapore; Department of Statistics and Applied Probability, National University of Singapore, Singapore. Electronic address: alex.richard.cook@gmail.com.

Abstract

BACKGROUND:

The lack of seasonality in influenza epidemics in the tropics makes the application of well-established temperate zone national vaccination plans challenging.
OBJECTIVES:

We developed an individual-based simulation model to study optimal vaccination scheduling and assess cost-effectiveness of these vaccination schedules in scenarios of no influenza seasonality and the seasonality regimes of Singapore, Taipei, and Tokyo.
METHODS:

The simulation models heterogeneities in human contact networks, levels of protective antibodies following infection, the effectiveness of the influenza vaccine, and seasonality. Using a no intervention baseline, we consider 3 alternative vaccination strategies: (1) annual vaccination for a percentage of the elderly, (2) biannual vaccination for a percentage of the elderly, and (3) annual vaccination for all elderly and a fraction of the remaining population. We considered 5 vaccination uptake rates for each strategy and modeled the estimated costs, quality-adjusted life years, and incremental cost-effectiveness ratios (ICERs), indicating the cost-effectiveness of each scenario.
RESULTS:

In Singapore, annual vaccination for a proportion of elderly is largely cost-effective. However, with fixed uptake rates, partial biannual vaccination for the elderly yields a higher ICER than partial annual vaccination for the elderly, resulting in a cost-ineffective ICER. The most optimal strategy is the total vaccination of all the elderly and a proportion of individuals from other age groups, which results in a cost-saving ICER. This finding is consistent across different seasonality regimes.
CONCLUSIONS:

Tropical countries like Singapore can have comparably cost-effective vaccination strategies as found in countries with winter epidemics. The vaccination of all the elderly and a proportion of other age groups is the most cost-effective strategy, supporting the need for an extensive national influenza vaccination program.
Copyright ? 2019 ISPOR–The Professional Society for Health Economics and Outcomes Research. Published by Elsevier Inc. All rights reserved.


KEYWORDS:

elderly; influenza; seasonal; tropics; vaccine

PMID: 31806190 DOI: 10.1016/j.jval.2019.07.001