Measles Cases in US Reach 30-Year High Amid Declining Vaccination Rates

Measles is resurging in the United States after years of being rare, with over 2,300 confirmed cases reported since the start of 2026. According to the Centers for Disease Control and Prevention (CDC), this is the highest number of measles cases recorded in the US in more than three decades, surpassing the total cases reported in 2025. The main outbreaks have occurred in South Carolina, Utah, and Arizona, with additional cases reported across other states. Health authorities warn that the actual number of infections may be higher due to underdiagnosis and underreporting.

Experts attribute the rise in measles cases primarily to declining vaccination rates. CDC data shows that vaccination coverage among kindergarten children has dropped to 92.5%, below the critical threshold of approximately 95% needed to maintain herd immunity and prevent outbreaks. Measles is highly contagious, spreading through airborne transmission via coughing, sneezing, or being in the same space as an infected person.

The World Health Organization (WHO) highlights that unvaccinated children, infants too young for vaccination, pregnant women, and immunocompromised individuals face the highest risk of severe complications such as pneumonia, encephalitis, and in rare cases, death. Despite its dangers, measles is almost entirely preventable through vaccination.

The outbreak in the US also holds relevance for Israelis, especially during the summer travel season. Health experts recommend that travelers, particularly children and at-risk groups, ensure their vaccinations are up to date before visiting countries experiencing active measles outbreaks.