UC Davis doctor urges vaccinations as California measles cases double

The United States is seeing the highest levels of measles since the 1990s. That includes dozens of cases in California so far this year.

CBS News Sacramento spoke with the head of UC Davis Children's Hospital about the rising cases and why measles specifically is the most infectious disease.

"We think about it as fever and a rash, but some patients end up being in the hospital," Dr. Dean Blumberg, the chief of pediatric infectious diseases at UC Davis Children's Hospital, said. "There can be complications. People can die from measles."

Blumberg said worrying about measles specifically is disappointing.

"It's really sad because we had measles under control," he said. "The U.S. had eliminated measles, meaning that there was no localized transmission."

Blumberg described measles as "likely the most contagious infection known to humans " because of how easily it spreads and how long it lingers.

"It's so infectious that people can be in a room and the virus can then be in the air and it can stay in that air for 1-2 hours after they leave the room," he explained.

So far this year in California, there have been at least 52 measles cases — double the cases in all of 2025 — and almost all of them were in unvaccinated people.

These mark the first measles outbreaks in the state since 2020.

"So we do need a relatively high immunity rate or immunization rate in order to prevent localized transmission. So for measles, that number is really high; that's 95%," Blumberg said. "Now although the overall rate is 95%, that's great, the problem is that the pockets of unimmunized people tend to congregate."

While most people recover fine, Blumberg says not to underestimate getting the disease.

"Twenty percent of people do have complications for measles that can include pneumonia, ear infections," he said. "People do end up in the hospital."

So his advice is simple: get the vaccine.

"There are a lot of implications from having measles," he said. "It's better to prevent it."

Blumberg says misinformation about measles vaccines is driving part of the latest measles outbreaks. He says parents should look to their pediatrician and the American Academy of Pediatrics to answer any questions about getting vaccinated.