The Tricky Math of Herd Immunity for COVID-19

June 30, 2020

(Quanta) – While much about the COVID-19 pandemic remains uncertain, we know how it will likely end: when the spread of the virus starts to slow (and eventually ceases altogether) because enough people have developed immunity to it. At that point, whether it’s brought on by a vaccine or by people catching the disease, the population has developed “herd immunity.” “Once the level of immunity passes a certain threshold, then the epidemic will start to die out because there aren’t enough new people to infect,” said Natalie Dean of the University of Florida.