Apoorva Mandavilli

Americans ages 65 and older should receive an additional dose of the latest COVID vaccine this spring, the Centers for Disease Control and Prevention said on Wednesday.

Measles, a highly contagious but preventable disease, is resurging in pockets of the United States, a warning of the dangers of the strengthening antivaccine movement.

Cases so far this year have already topped the U.S. total in 2023. Unvaccinated travelers account for most infections.

Scientists studying the virus’s continuing evolution, and the body’s immune responses, hope to head off a resurgence and to better understand long Covid.

A citizen-science collaboration in New York has turned up a half-dozen birds infected with the avian flu virus.

The infections, which include one associated human case, add another worrying wrinkle to a global outbreak that has devastated bird and marine mammal populations.

New regimens in development, including once-weekly pills and semiannual shots, could help control the virus in hard-to-reach populations.

H5N1, an avian flu virus, has killed tens of thousands of marine mammals, and infiltrated American livestock for the first time. Scientists are working quickly to assess how it is evolving and how much of a risk it poses to humans.