Effect of vaccination rates on the prevalence and mortality of COVID-19

Abstract

By looking at trends in global epidemic data, we evaluate the effectiveness of vaccines on the incidence and mortality from the delta variant of COVID-19. By comparing countries of varying vaccination levels, we find that more vaccinated countries have lower deaths while not having lower cases. This cannot be explained by testing rates or restrictions, but can be partly explained by the most susceptible countries also being the highest vaccinated countries. We also find that during the period when many countries have high vaccination rates, cases and deaths are both increasing in time. This seems to be caused by the waning of the protection vaccines grant against infection.