Across US counties, vaccination rates have a statistically significant downward effect on the Covid-19 death rate, as of August 7. Controlling for poverty rates, age, and temperature lowers the magnitude of the estimate a little. Using the Biden-Trump vote in the 2020 election as an instrument for vaccination rates raises the magnitude of the estimate a bit. Presumably it corrects for a positive effect of observed covid deaths on the decision to get vaccinated. Overall, the beneficial effect holds up.