The WHO and CDC say there were about 10.3 million cases of measles last year, up 20 percent from 2022. Children are especially susceptible to complications.

Because of global gaps in vaccination coverage, 57 countries experienced measles outbreaks in 2023, the agencies noted, representing a nearly 60% increase from 36 countries in 2022. Nearly half of all outbreaks occurred in the African region, according to the WHO.

More than 10.3 million people caught measles last year, a 20% increase from a year earlier, according to a joint report by the World Health Organization and US Centers for Disease Control and Prevention.