U.S. measles cases have hit a 35-year high as vaccination rates fall. The federal Centers for Disease Control (CDC) received reports of nearly 2,500 confirmed cases from January through early August, more than in all of 2025. Outbreaks are in 45 states and Washington, D.C. Measles is usually the first disease to rise when vaccine levels dip, because it is extremely contagious. It brings fever and an itchy rash, which usually last a few days or a week. But serious complications can include ear infections, pneumonia (lung infection) and occasionally brain swelling known as encephalitis (pronounced en-seff-uh-LIGH-tuhss). That last condition can casue convulsions and leave a child deaf or with intellectual disability.

The disease was considered eliminated from this country in 2000, but a decades-long slide in childhood vaccination rates changed that and has brought outbreaks over the past two years as the virus gains a new foothold. Ninety-three percent of infected people are unvaccinated, the CDC says, and most are school pupils. Measles is usually the first disease to rise when vaccine levels dip, because it is extremely contagious.

Vaccination rates dropped as activists pushed to limit immunization requirements in schools, citing a 1998 study linking the vaccine to autism. That research was later retracted and its British author lost his medical license, but the damage had been done. Thousands of parents received exemptions from state mandates. "We have joined the rank of countries where vaccination is not reaching the levels needed to protect all of our children," said Dr. Richard Besser, a pediatrician and head of a national health foundation. Health Secretary Robert F. Kennedy Jr., a longtime vcaccine skeptic, now encourages parents to protect children. "A measles vaccine is effective," he said Sunday on CNN. "It stops measles in about 97% of the cases."

Doctor says: "Our communities are vulnerable, not just from measles, but from whooping cough, meningitis, chicken pox and other diseases that are readily controllable with vaccines. We're on a crash course." -- Dr. Richard Besser, pediatrician in Princeton, N.J.

State official says: "Every missed or delayed vaccine is a missed opportunity to protect a child and their entire classroom." -- Dr. Natasha Bagdasarian, chief medical executive of Michigan

Science journalist writes: "Distrust in vaccines in the U.S. came long before President Trump, but has grown in recent years because of misinformation that circulated online during the Covid-19 pandemic and in podcasts and social media since then." – Julia Musto, The Independent (British newspaper)