A measles outbreak has emerged in the United States, primarily affecting rural West Texas. Health officials have confirmed over 150 cases, making it the largest outbreak in recent years. Additional cases have been detected in New Mexico, Alaska, California, Georgia, Kentucky, New Jersey, New York, Pennsylvania, and Rhode Island. The Centers for Disease Control and Prevention (CDC) considers an outbreak to be three or more related cases, with three clusters meeting this definition in 2025. Measles spreads through airborne transmission and remains highly contagious. Studies indicate that an infected individual can spread the virus to about 15 others in unvaccinated communities. Experts attribute the increase in cases to declining immunization rates. Authorities are enforcing urgent measures to control the outbreak. The CDC has deployed specialists to Texas to support containment efforts. Medical experts confirm that the measles, mumps, and rubella (MMR) vaccine is the most effective defense. The CDC recommends two doses to ensure immunity. Studies emphasize that a 95% vaccination rate is necessary to prevent outbreaks. However, immunization rates have dropped, partly due to COVID-19 disruptions. Epidemiologists highlight the importance of reinforcing vaccination programs to curb transmission.