Behavioral Responses to Risk Promote Vaccinating High-contact Individuals First

If COVID-19’s reproduction number was constant, vaccinating elderly first minimized deaths. However, incorporating risk-driven behavior/policy changes enhances fit to data and prioritizes vaccinating high-contact individuals. Deaths grow exponentially until people are compelled to reduce contacts, stabilizing at levels obliging higher-contact groups to sufficiently cut interactions. Vaccinating those groups out of transmission saves lives and speeds everybody’s return to normal life.