Epidemiology

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

The rapid spread of new variants such as Omicron offers clues to how SARS-CoV-2 is adapting and how the pandemic will play out over the next several months

Today we bring you a new episode in our podcast series COVID, Quickly. Every two weeks, Scientific American’s senior health editors Tanya Lewis and Josh Fischman catch you up on the essential developments in the pandemic: from vaccines to new variants and everything in between.

You can listen to all past episodes here.

The numerous changes in the coronavirus’s spike protein could have arisen in an isolated population or an immunocompromised person—or animals

Researchers are racing to determine whether a fast-spreading coronavirus variant poses a threat to COVID vaccines’ effectiveness

A mechanism known as “original antigenic sin” protects some people from flu. Whether it helps immune reactions to coronaviruses is still unclear