CDC warns additional measles cases expected in the spring and summer
Updated April 30, 2026, 7:42 a.m. ET
The Centers for Disease Control and Prevention warned this week that additional measles cases in the United States can be expected in the coming months as the busy summer travel season approaches.
In guidance sent to state and local health departments on April 27, federal health officials urged public health agencies across the United States to remain vigilant and prepared for more measles cases in the upcoming months. The CDC noted that travel surges during the spring and summer raise the risk of further spread.
“With continued measles transmission in areas across North America and expected increases in international and domestic travel and large events during spring and summer, additional measles cases are anticipated in the coming months,” the CDC said in the guidance.
The agency reminded state and local health departments to immediately report suspected measles cases — within 24 hours — to the CDC and through the National Notifiable Disease Surveillance System. Public health agencies were also recommended to ensure that hospitals have clear procedures for reporting measles cases to authorities.
The CDC advised public health agencies to document and report details of each case, including close contacts and locations visited while a person was infectious. Active surveillance should be conducted to identify any additional suspected cases and quickly transport specimens for laboratory confirmation, the CDC said.
The agency encouraged outreach to under-vaccinated communities and suggested using state-based syndromic surveillance systems to detect changes in health care–seeking behavior for fever and rash illnesses or signs of vitamin A toxicity.
The guidance was issued as measles cases continue to be recorded in the United States. The CDC said 1,792 confirmed measles cases have been reported across the country as of April 23.
Measles cases in the United States
Among the 1,792 confirmed measles cases, the CDC said 1,782 were recorded in 36 states. A total of 10 measles cases were reported among international visitors to the United States.
CDC data shows that there have been 22 new outbreaks reported in 2026, with 93% of confirmed cases being outbreak-associated, which is defined as three or more related cases. About 92% of cases are among people who are unvaccinated or whose vaccination status is unknown.
In 2025, a total of 2,288 confirmed measles cases were reported across the United States, according to the CDC. Among those cases, 2,263 were recorded in 44 states, while 25 cases were reported among international visitors to the United States.
Of the 2,288 cases, 26% occurred in children under 5, while 44% were reported among ages 5 to 19, the CDC said. The agency also reported that 243 patients were hospitalized last year, including 106 patients under age 5.
The CDC said 93% of the country’s measles cases in 2025 were in patients who either had not been vaccinated or had an unknown status. There have been three confirmed deaths, including two children, in West Texas.
Vaccination coverage among U.S. kindergartners has decreased from 95.2% during the 2019–2020 school year to 92.5% in the 2024–2025 school year, according to the CDC.
Measles was declared eliminated in the United States in 2000, meaning the virus was no longer spreading continuously within the country. That elimination status is now under review, with the Pan American Health Organization delaying a decision until November.
Best protection against measles
Measles is highly contagious and can spread when an infected person coughs or sneezes, the CDC said. People can also be infected by breathing contaminated air, where it remains infectious for up to two hours, or by touching their mouth, eyes, or nose after contact with a contaminated surface.
Measles symptoms typically appear seven to 14 days after contact with the virus and commonly include high fever, cough, runny nose, and watery eyes, according to the CDC. A measles rash appears three to five days after the onset of the first symptoms.
Complications from measles include ear infections, hearing loss, pneumonia, croup, diarrhea, blindness, and swelling of the brain, the CDC said. Even in healthy children, measles can cause serious illness and death.
In unvaccinated pregnant women, measles may cause premature birth or a low-birthweight baby.
The CDC estimates that about 1 in 5 unvaccinated people in the United States who get measles will need hospitalization. Health experts have underscored that the best protection against the disease is the vaccine, either given alone or as part of an MMR shot or a measles-mumps-rubella-varicella (MMRV) vaccine.
Two doses of the MMR vaccine provide 97% protection against the virus, according to the CDC. Children typically receive their first vaccine dose at 12 to 15 months and a second at 4 to 6 years.
Adults born before 1957 are presumed to have acquired immunity as they most likely had measles during childhood, according to the National Foundation for Infectious Diseases.
Contributing: Adrianna Rodriguez, Ken Alltucker, and Mary Walrath-Holdridge, USA TODAY; Reuters