"The alarming increase in measles cases and deaths globally is a clear warning sign," says Dr. John Brownstein, an innovation officer at Boston Children's Hospital, per ABC News.
He's referring to a new report from the World Health Organization and Centers for Disease Control and Prevention that shows an 18% increase in measles cases from 2021 to 2022 and a 43% increase in deaths from 2021 to 2022.
In the US, 41 measles cases have been reported so far this year, with 1,274 people sick in at least 31 states, the Washington Post reports.
Most of the cases were among young people who weren't vaccinated, and most outbreaks occur in groups of people who are not up to date on their vaccines.
The CDC notes that a vaccination coverage rate of 95% with both doses is necessary to protect communities from outbreaks.
The report shows that 37 countries experienced large outbreaks in 2022 compared to 22 countries in 2021.
The majority of the countries with outbreaks were located in Africa, as well as a handful in the Eastern Mediterranean region.
The report also shows that 33 million children missed a measles vaccine dose in 2022, including about 11 million getting their first shot but missing their second dose.
Measles can cause serious health complications, especially in children younger than 5, according to the CDC.