Post-infection immunity was very protective against Delta, the C.D.C. reports, but vaccines still offer the best defense.

Starbucks baristas in training in Cheektowaga, N.Y. The company said the vast majority of its workers were vaccinated.Credit…Libby March for The New York Times The Supreme Court’s ruling last week shutting down the Biden administration’s effort to enlist large employers in its vaccination campaign, experts said, would trigger a new wave of uncertainty about how…

Can Omicron Cause Long Covid?

It found that people who had received even one dose of a Covid vaccine before their infection were seven to 10 times less likely to report two or more symptoms of long Covid 12 to 20 weeks later. The study, which was led by Michael Simon, Arcadia’s director of data science, and Dr. Richard Parker,…

In Sewage, Clues to Omicron’s Surge

Dr. Hopkins consults weekly with wastewater screeners to determine where the city should funnel resources. When officials from the Houston program noticed that the sewage in one ZIP code, a largely Hispanic neighborhood, had unusually high levels of the virus week after week, they distributed testing and cleaning supplies and multilingual educational materials about the…

What Have You Dreamed About Lately?

Welcome. I keep forgetting how I know things. With so much of life transpiring through screens — Zoom calls, group texts, long articles saved to read later, Netflix series half-paid-attention-to while scrolling through Instagram — I’ll find myself recalling a fact or a story, unable to identify the source of the information. Did this dimly…