San Francisco was a few days into sheltering in place in March 2020 when Dr. Maya Petersen got a surprising and urgent request: Health officials wanted to know whether she could put together a model that would help them forecast what was shaping up to be a horrifying pandemic.
Petersen, an epidemiologist at UC Berkeley’s School of Public Health who had been studying HIV for more than a decade, immediately thought no, surely there must be someone better suited to the job. “I don’t know anything about COVID,” she recalled thinking. And then, of course, she realized: No one knew anything about COVID-19.
So she said yes. And almost overnight, Petersen and her statistician husband, working in the Bernal Heights home where they were holed up with their children like everyone else in the city, built a disease model that would guide some of the most critical decisions in San Francisco’s pandemic response.