Virus

We don’t yet know if H5N1 bird flu will spill over from animals to infect a large number of humans.…

But the scope of the outbreak among cattle remains uncertain, and little human testing has been done.

The early results suggest that pasteurization is killing the H5N1 virus in milk, something that regulators were not certain of.

There is no evidence that the milk is unsafe to drink, scientists say. But the survey result strongly hints that…

Walking through the intensive care unit is often a lesson in how much there is to fear. Just a few…

Scientists doing “gain-of-function” research said that heightened fears of lab leaks are stalling studies that could thwart the next pandemic…

America has begun to treat Covid-19 like just any other disease — boosters are now arriving on an annual fall…

Here’s who should get the flu, Covid and R.S.V. vaccines, and when.

Though agency advisers had some safety concerns, the Pfizer shot is expected to be available before the winter R.S.V. season.

Federal regulators plan to authorize an additional dose for seniors and immunocompromised people in the coming weeks, ahead of the…