Do You Need a Measles Vaccine Booster?

In the wake of a measles outbreak that originated in Texas and is now thought to have spread to four other states, many individuals may be questioning whether they should receive a measles vaccine booster shot. Measles is a highly contagious airborne illness that can result in severe complications, including death. It is preventable through the measles, mumps, and rubella (MMR) vaccine, typically given in childhood in two doses. The U.S. declared measles eliminated over two decades ago due to a successful vaccination program. However, a decline in vaccination rates in recent years has led to a surge in measles cases. In 2024, there were 285 reported measles cases in the U.S., but within the first four months of 2025, the number of confirmed cases reported to the CDC has risen to 800. Of these cases, 96% were in individuals who were either unvaccinated or had unknown vaccination status.

As of 2025, two unvaccinated children in Texas have died from measles-related complications, with a third unvaccinated adult in New Mexico testing positive for measles posthumously. The cause of death is still being investigated. Prior to this year, the last confirmed measles fatality in the U.S. occurred in 2015.

Health experts emphasize that the most effective way to shield oneself from measles is by getting vaccinated. The CDC states that the MMR vaccine is safe and two doses are 97% effective against measles. Even those who did not receive the MMR vaccine in childhood can still get vaccinated later in life. While most individuals who receive the MMR vaccine are protected for life, there are no official recommendations for a third dose during a measles outbreak.

Dr. Ravi Jhaveri, a pediatric infectious diseases specialist at Northwestern University Feinberg School of Medicine, notes that measles is genetically stable, and two doses of the MMR vaccine provide adequate protection. Booster shots may be necessary for diseases with high genetic variability, such as the flu and COVID-19, or for diseases like tetanus where immunity diminishes over time. However, for measles, two doses of the MMR vaccine are typically sufficient to maintain immunity.

The ongoing measles outbreak primarily affects unvaccinated individuals, emphasizing the importance of vaccination. Encouraging those who are hesitant to see the benefits of vaccination is crucial in preventing future outbreaks.