Consumer willingness to pay for a hypothetical Chikungunya vaccine in Brazil and the implications

Background: Chikungunya fever is an important infectious disease transmitted by the bite of Aedes genus mosquitoes infected with the Chikungunya Virus (CHIKV). Information about consumers’ willingness to pay (WTP) for a hypothetical vaccine against CHIKV can help discussions about prices and funding in countries with limited resources. Methods: Cross-sectional study among adult residents of Minas Gerais, Brazil, asking if they were willing to pay the price for a hypothetical chikungunya vaccine defined by the authors with an effective protection of 80% and the possibility of local and systemic side-effects. Residents were provided with information if not familiar with the virus. The price was randomly varied between participants in five values: US$11.69 (45.00BRL), US$23.38 (90.00BRL), US$46.75 (180.00BRL), US$93.51 (360.00BRL) and US$187.90 (720.00BRL). We included this aspect due to issues with any anchoring effect. Results: 496 individuals were interviewed. Among these, 23 were excluded. Most of the respondents were female (57.3%), had completed at least high school (90.7%), were employed (87.7%) and had private health insurance (62.6%). The median value of the WTP was US$ 31.17 (120.00 BRL) for a unique dose vaccine. There was a statistical significant correlation with monthly family income and access to private health insurance. Conclusion: This study can contribute to decision-making about potential prices for a CHIKV vaccine when it becomes available in Brazil. We also showed the anchoring effect as a possible influence on consumers’ WTP in studies with similar techniques. Finally, we encourage the development of a chikungunya virus vaccine to benefit the Brazilian population.