The relation between timing of vaccinations and levels of confirmed cases of COVID-19 in society: When to roll out vaccination to minimize infections?

This study analyzes the relations between doses administrated of vaccines for Coronavirus disease-2019 (COVID-19) and confirmed cases from March to May 2021 to find out the optimal level of doses administrated per 100 inhabitants, which can lead to a reduction in the diffusion of COVID-19 cases. Findings reveal that a delay of vaccination in population, it moves up the optimal value of doses administrated per 100 inhabitants from 58.5 to more than 86 per 100 people, with consequential damages and long-run deterioration of socioeconomic systems. This study suggests that the optimal policy to pandemic threats is the early, rapid, nationally vaccination rollout for an effective reduction of the spread of infectious disease that reduces negative effects in society.