The Premonition: A Pandemic Story Highlight

the more people needed to be infected before the herd was theoretically safe. Measles’ reproductive rate of 18, on the high end, implies that ninety-five percent of the population needs to be immune to measles before measles stops spreading. That’s why we have as our goal to vaccinate 95 percent of the population against measles. Before COVID-19 stopped spreading, two-thirds of Californians would need to become infected.