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.