Scientists were slow to recognize that Covid spreads through the air. Some are now trying to get ahead of the bird flu.

Lifesaving treatment and prevention programs for tuberculosis, malaria, H.I.V. and other diseases cannot access funds to continue work.

Vague federal directives have led to frantic action, and perhaps overreaction, before a Friday deadline.

When we face some risk of a bird flu pandemic, do we want to entrust our health to a man who has fought lifesaving vaccines?

Mr. Kennedy appears to have most Republicans behind him as he seeks the job of health secretary, though he couldn’t escape his past stances on vaccines and abortion.

In recent months, bird flu has started raising red flags among scientists and public health officials. Apoorva Mandavilli, a New York Times reporter who covers infectious diseases, explains why we need to start taking bird flu seriously.

It could be answered by Times journalists and experts in a future Ask Well column.

R.F.K. Jr. and others have blamed the ingredient for allergies and other illnesses. Scientists say it actually bolsters the immune response.

Scientific meetings were canceled, and research data on the bird flu outbreak was delayed, amid confusion over the directive.

Public health experts say U.S. withdrawal from the W.H.O. would undermine the nation’s standing as a global health leader and make it harder to fight the next pandemic.

Conscious of the health risks of alcohol, more people are experimenting with cutting back on drinking.

In the final days of the Biden administration, the F.D.A. is moving ahead with a proposal to require companies to produce a less addictive product for traditional smokers.

The agency issued designs for front-of-package lists that food companies would be required to include.

Medical historians say that the phrase “Make America Healthy Again” obscures a past during which this country’s people ate, smoked and drank things that mostly left them unwell.

By 2060, new dementia cases per year could double to one million because of the growing population of older Americans, a study predicts.

In its original form, the virus survives in just two countries. But a type linked to an oral vaccine used in other nations has already turned up in the West.

Researchers see a growing health danger from the vast plumes of pollution spawned by wildfires like the ones devastating Los Angeles.

While cases are climbing in China, the situation is very different from what it was when Covid-19 emerged five years ago, medical experts say. HMPV has circulated in humans for decades.

A quarter of nations worldwide have health risk labels on alcohol. But only South Korea has a warning about liver cancer.