Measles Surge Signals Risk of Other Vaccine-Preventable Diseases

The surging number of measles cases around the world is a stark warning sign that outbreaks of other vaccine-preventable diseases could be next, the World Health Association warned Friday.

“It’s crucial to understand why measles matters,” said Dr. Kate O’Brien,director of the WHO’s Department of Immunization,vaccines and Biologicals.”Its high transmissibility means that even small drops in vaccine coverage can trigger outbreaks, like a fire alarm going off when smoke is detected first.”

Measles is often the first disease to appear when vaccination rates decline overall.

“When we see measles cases, it signals that gaps likely exist for other vaccine-preventable diseases like diphtheria, whooping cough, or polio, even if they aren’t immediatly apparent,” O’Brien said at a media briefing Monday, ahead of the WHO’s Progress Toward Measles Elimination report, published Friday in its Weekly Epidemiological Record.

Whooping cough cases are also rising in the United States and are on track to reach a decade high. The Centers for Disease Control and Prevention reports more than 20,000 whooping cough cases so far in 2025.

In 2024, the report estimates 11 million measles infections worldwide, nearly 800,000 more than in 2019.

Last year, 59 countries reported large measles outbreaks. The United States joined this list in 2025.

Elimination status threatened

Ongoing outbreaks threaten the measles elimination status of some countries.

Elimination means a virus has stopped spreading within a specific country or region. (Only smallpox has been eradicated worldwide.)

In 2024, the WHO reported 81 countries had achieved elimination status.Canada eliminated measles in 1998, and the United States followed in 2000.