With summer travel season approaching, Oregon Health Authority (OHA) encourages people to make sure they are protected against measles. Getting the MMR vaccine (for measles, mumps and rubella) is the most effective prevention tool against the highly contagious virus.
Although Oregon has not reported any cases, 12 states, including California, have reported cases of measles since the first of the year. In 2024, Oregon recorded 31 confirmed cases—its highest measles count in more than 30 years—during an outbreak among unvaccinated people, including two children under five years old. Reduced vaccination rates are driving the outbreaks.
“Measles is an amazingly contagious virus that unfortunately in recent years has re-emerged in our communities, primarily due to a declining percentage of people who are getting vaccinated,” said Paul Cieslak, M.D., medical director for communicable diseases and immunizations at OHA’s Public Health Division.
“The good news is that we have a highly safe and effective vaccine—it is our strongest line of defense and the best way to keep yourself, your children and your community safe. If you have questions about the vaccine, we encourage you to talk to your healthcare provider about your concerns,” said Dawn Nolt, M.D., M.P.H., professor of pediatrics (infectious diseases) in the OHSU School of Medicine.
In addition to reducing the risk of transmission, school-age children who receive vaccination can help families avoid having to isolate at home for several weeks if they are exposed to measles. Additionally, state law requires an unvaccinated child exposed to the virus to be excluded from school or childcare during the period when they could become sick, which is usually 21 days after exposure. This exclusion period can be extended if there are more measles cases.
For adults born before 1957, vaccination is not needed as they are presumed to be immune. The reason for that is before the measles vaccine was first available to the public in 1963, virtually all children would have contracted measles by their teenage years, making them immune for life.
People born in 1957 or later, however, could still benefit from the vaccine because they would have been at least six years old in 1963. At that age, there was still a meaningful chance they hadn’t been exposed to measles yet and could benefit from the new vaccine.
People who can document receiving the measles vaccine series at some point in their lives or have documentation showing a previous measles diagnosis or laboratory evidence of immunity can be confident they are immune and do not need to receive the MMR vaccine.