Epidemiology

The fungal pathogen that causes valley fever is thriving in the American West—and intensifying atmospheric rivers could be to blame

A new study found persistent effects of smoking on the adaptive immune system, but how this translates to health risks remains unclear

Four years into the pandemic, many people have had COVID more than once—but the health consequences of repeat infections are not yet clear

Scientists are watching closely to see whether avian influenza will reach Antarctica before this year’s penguin chicks disperse for the season

Very young children’s developing immune systems respond to the COVID-causing virus SARS-CoV-2 very differently than do those of adults

“We’re still in a pandemic,” says a lead COVID official with the World Health Organization

Measles cases have ticked up in the U.K. following lower rates of MMR vaccination, and the U.S. could see similar outbreaks

A spillover of the neurological disease to humans from deer, elk, and other animals could be devastating

Ancient DNA recovered from Brazilian remains shows that syphilis and other treponemal diseases originated some 10,000 years earlier than previously thought

Infants born to people who had COVID while pregnant are at a higher risk of respiratory distress, but vaccination greatly lowers the risk

Levels of opioids and other drugs in sewage could help public health authorities home in on drug use and target treatment efforts

Measles is extremely infectious. Vaccines provide good protection, but some adults may need a top-up shot