How big is the latest U.S. coronavirus wave? No one really knows.

Eileen Wassermann struggles to calculate her daily risks at this stage of the coronavirus pandemic — with infections drastically undercounted and mask mandates gone. The immunocompromised 69-year-old ensconces herself in her SUV for the half-hour ferry ride across the Puget Sound from her home on Bainbridge Island to Seattle, where she undergoes treatment for the rare inflammatory condition sarcoidosis. A retired scientist and lawyer who worked with drug companies, Wassermann is comfortable analyzing coronavirus data. But she said current numbers, which don’t account for most at-home test results, are unreliable. “My mode, which sounds ridiculous maybe at this point, is to be as cautious as I was at the beginning of 2020,” said Wassermann, who has received two booster doses of the coronavirus vaccine.