Health experts have been encouraging everyone who can get the COVID-19 vaccine to get it. They want to reach a threshold called herd immunity. What does that mean? Herd immunity occurs when a large enough percentage of the population is vaccinated (and thus immune to a disease) that the illness can no longer spread through the community. The exact fraction that needs to be vaccinated to achieve herd immunity is different for every disease. Scientists estimate for COVID-19 it will be larger than 60%. Dane County in Wisconsin has vaccinated just about 70% of residents and has seen numbers of infection drop significantly. We are only observing about 5 to 10 cases a day and 55% of these are coming from outside the Madison area. UW-Madison has had spectacular success at vaccinating its population, achieving a vaccination rate of over 85%. From June 13th until July 1st there were no cases of COVID-19 in the UW-Madison community. COVID-19 can be controlled and likely eradicated, if we are willing to get the dang shot.