Surging measles cases are 'fire alarm' warning that other diseases could be next

The World Health Organization has issued a warning that the rising number of measles cases worldwide is a significant indicator that other vaccine-preventable diseases could soon follow. Dr. Kate O'Brien, director of the WHO's Department of Immunization, Vaccines and Biologicals, emphasized that measles often appears first when vaccination rates decline, acting as a 'fire alarm' for potential outbreaks of diseases like diphtheria, whooping cough, and polio. In 2024, there were an estimated 11 million measles infections globally, with 59 countries reporting large outbreaks in 2025, including the United States. The ongoing outbreaks threaten the measles elimination statuses of some countries, as the key factor for losing this status is the continuous spread of the virus for a full year. The United States is at risk of losing its elimination status if current cases can be traced back to a Texas outbreak that began in January.