Unvaccinated Children Drive Oregon's Largest Measles Outbreak Since 1991

PORTLAND, Ore. (KATU) -- An increasing number of parents in Oregon are choosing not to vaccinate their children, according to the Oregon Health Authority. Last school year, 9% of kindergartener families sought exemptions from one or more required vaccines, marking the highest rate ever recorded in the state.

This trend comes as Oregon faces its largest measles outbreak since the early 1990s, with all reported cases involving unvaccinated individuals. Despite the U.S. declaring endemic measles eliminated in 2000, importations continue, and prolonged outbreaks in 2019 threatened the nation's measles elimination status.

The Centers for Disease Control and Prevention (CDC) has emphasized the importance of vaccination, particularly before international travel, to prevent measles importations into U.S. communities. The CDC reported that from January, 2020 to March, 2024, a total of 338 U.S. measles cases were documented, with 29% occurring in the first quarter of 2024. Almost all cases involved unvaccinated individuals or those with unknown vaccination status.

The CDC and WHO report that vaccination programs help shift the burden of disease away from infancy, the age group with the highest case fatality, thereby reducing measles mortality.

Feb. 19 marks Oregon's School Exclusion Day, when students who have not received the required vaccines or obtained an exemption will be excluded from attending school until a resolution is reached.