Epidemiology

Scientists are just starting to unravel the disease’s long-term cardiac effects

Historians of the 1918 influenza pandemic discuss lessons for what the future of COVID might look like

A CDC database of sewage data from communities around the nation could provide earlier warning of outbreaks and new viral variants

Opinion among physicians and scientists still ranges widely on how quickly to proceed

The reports’ authors say that the novel coronavirus, or SARS-CoV-2, jumped from animals sold at the market to people twice in late 2019—but some scientists want more definitive evidence

Vaccination definitely lowers the odds, but the exact answer is hard to find

Infectious disease expert William A. Haseltine cautions that a coronavirus variant could emerge with the transmissibility of Omicron and the deadliness of the original SARS

Hamsters are only the second species known to have spread SARS-CoV-2 to humans

It depends, but vaccinated people should generally wait five days after exposure before taking an antigen test. Here’s why

COVID shutdowns limited the spread of influenza in 2019–2020. Several factors could mean this season will be more severe

It’s too soon to know if the variant causes milder COVID, but its transmissibility and ability to evade vaccines are still cause for concern

The new coronavirus variant may be better than other versions at avoiding human immune defenses—but that ability may change in different countries