Multi-scale modeling and analysis of vaccine prevention and control strategies for Chikungunya disease

In response to the wait-and-see attitude arising from environmental uncertainty and the costs associated with prevention and control during the promotion of Chikungunya vaccine, this study evaluates the effectiveness of vaccine strategies using multi-scale dynamic models. First, a Chikungunya periodic model driven by temperature factors is established to quantify the synergistic effects of incomplete vaccination coverage and the seasonal activity of mosquitoes. It is found that neglecting the temperature factor will lead to an underestimation of the required vaccination rate. And a comprehensive measure combining vaccination and physical protection is proved to be more cost-effective than combined insecticide-based vaccination. Second, an autonomous model corresponding to the periodic model under average annual temperature is constructed. This model is analyzed to determine the threshold for vaccine coverage and the extinction conditions for Chikungunya disease, providing a rapid tool for resource assessment. Furthermore, time-varying control variables are introduced into the autonomous model, and the optimal strategy is obtained through theoretical analysis. The numerical results in the three different control scenarios indicate that when the proportion of high-risk groups is low, vaccination targeting only high-risk groups may fail, while dynamic vaccination adjustments can partially compensate for seasonal risks when using the annual average parameter.