Cost-Effectiveness and Impact of a Targeted Age- and Incidence-based West Nile Virus Vaccine Strategy

• Published in: Clinical infectious diseases Vol. 73; no. 9; pp. 1565 - 1570
• Main Authors: Curren, Emily J, Shankar, Manjunath B, Fischer, Marc, Meltzer, Martin I, Erin Staples, J, Gould, Carolyn V
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 02.11.2021
• Subjects: Cost-Benefit Analysis; Humans; Incidence; United States - epidemiology; West Nile Fever - epidemiology; West Nile Fever - prevention & control; West Nile virus; West Nile Virus Vaccines; United States; cost-effectiveness; West Nile virus; impact; vaccination
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1093/cid/ciab540

Abstract Background West Nile virus (WNV) is the leading cause of arboviral disease in the United States and is associated with significant morbidity and mortality. A previous analysis found that a vaccination program targeting persons aged ≥60 years was more cost-effective than universal vaccination, but costs remained high. Methods We used a mathematical Markov model to evaluate cost-effectiveness of an age- and incidence-based WNV vaccination program. We grouped states and large counties (≥100 000 persons aged ≥60 years) by median annual WNV incidence rates from 2004 to 2017 for persons aged ≥60 years. We defined WNV incidence thresholds, in increments of 0.5 cases per 100 000 persons ≥60 years. We calculated potential cost per WNV vaccine-prevented case and per quality adjusted life-years (QALYs) saved. Results Vaccinating persons aged ≥60 years in states with an annual incidence of WNV neuroinvasive disease of ≥0.5 per 100 000 resulted in approximately half the cost per health outcome averted compared to vaccinating persons aged ≥60 years in the contiguous United States. This approach could potentially prevent 37% of all neuroinvasive disease cases and 63% of WNV-related deaths nationally. Employing such a threshold at a county level further improved cost-effectiveness ratios while preventing 19% and 30% of WNV-related neuroinvasive disease cases and deaths, respectively. Conclusions An age- and incidence-based WNV vaccination program could be a more cost-effective strategy than an age-based program while still having a substantial impact on lowering WNV-related morbidity and mortality. A West Nile virus (WNV) vaccination program targeting age groups and locations with elevated neuroinvasive disease incidence is more cost-effective than a national or age-based strategy alone and still would have a substantial impact on lowering WNV-related morbidity and mortality.