Optimal public health strategy during an influenza outbreak

Although vaccine has proven to be the best preventive method to reduce risk of flu infection, the coverage often remains below the herd-immunity level due to individuals’ perceptions towards the vaccination and the severity of disease outbreak. This, however, brings challenges to public health for strategic decision-making in controlling flu outbreak every year. To understand the impact of behavioral issues on public health decision-making to control flu, we define vaccination decision in population as a two-strategy pairwise-contest game and integrate with the disease process model to consider vaccination during a flu outbreak. We use optimal control theory to identify the best possible strategy for public health to reduce infection at a minimum cost. Our analysis shows that the cost of public health initiatives can be minimized by putting the effort in the beginning and end of the outbreak rather than during the peak. We also consider vaccination with evolving risk perception and infection with high severity such as disease-induced death. Our model demonstrates a feed-forward mechanism in the dynamics of vaccination and exhibits an increase in vaccine uptake as the risk perception decreases with more coverage. It confers that public health effort towards disseminating disease severity or actual vaccination risk might accelerate the vaccination coverage and mitigate the infection faster.