President Javier Milei has sought to align Argentina with President Trump, even if it means breaking with previous allies and partners.

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

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?

Robert F. Kennedy Jr., the nominee to lead the Department of Health and Human Services, made disputed claims before the Senate Committee on Health, Education, Labor and Pensions.

President Trump’s decision to pull out of the international health agency could deprive the United States of crucial scientific data and lessen the country’s influence in setting a global health agenda.

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.

A pandemic is not inevitable, scientists say. But the outbreak has passed worrisome milestones in recent weeks, including cattle that may have been reinfected.

A new analysis that began under the Biden administration is released by the C.I.A.’s new director, John Ratcliffe, who wants the agency to get “off the sidelines” in the debate.

Dr. Anthony S. Fauci, who was one of the nation’s top health officials for decades, had received death threats during the coronavirus pandemic. He has hired his own security detail.

As trust in medicine declines and vaccine hesitancy spreads, doctors are changing how they talk about lifesaving childhood shots.

What makes this dynamic in the new Trump administration so fascinating?

The only possibility for a second Trump term that would be truly surprising is a period of unlooked-for calm.

In a wide-ranging interview, Xavier Becerra, President Biden’s health secretary, defended his tenure and hinted that he might run for governor of California.

Airlines have been increasingly outsourcing repair and upkeep work to other countries, but experts and consumer groups disagree about its impact on safety.

Biden’s disastrous debate performance highlighted age concerns.

The industry is pumping ever more oil and natural gas, but it is doing so with only about three-quarters as many workers as it employed a decade ago.

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.

But the report, on the experiences of 13 patients, found that the drug had no benefit for some people and that some who benefited said the improvement didn’t last.

Some older Americans have come to depend on virtual consultations with doctors, covered by Medicare. To keep that option in the future, Congress will have to act quickly.

While some agree with Robert F. Kennedy Jr. that the agency needs reform, their ideas for fixing it are very different from his.