Inadequate immunisation is driving the global surge in measles cases, with an estimated 10.3 million cases in 2023 – a jump of 20% since 2022.

This is according to new estimates from the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC). 

A total of 57 countries experienced large outbreaks in 2023, in comparison to 36 countries in the previous year. 

Europe’s measles cases increased by 200% – from 100,000 cases to just over 300,000 cases.

An estimated 107,500 people, mostly children under the age of five, died of measles in 2023, an 8% decrease from the previous year.

“This slight reduction in deaths was mainly because the surge in cases occurred in countries and regions where children with measles are less likely to die due to better nutritional status and access to health services,” according to Dr Christine Dubray, CDC Measles Elimination Team Lead

But Dr Natasha Crowcroft, WHO senior technical advisor on measles, said it is “very hard with the level of data we have” to be able to say why this had happened.

“Vaccine hesitancy plays a part in all regions of the world, so we know that’s in there somewhere,” said Crowcroft.

However, she said that deaths were in vulnerable communities with high rates of malnutrition, poor health services and often also conflict. 

“In the African region, the number of deaths increased by 37%,” she said. Africa had  4.5 million cases in 2023, and 71% of global deaths.

At least 95% of children need to be vaccinated with two doses of the measles vaccine to prevent outbreaks of one of the world’s most contagious viruses.

CDC and WHO are founding members of the Measles & Rubella Partnership (M&RP), a global initiative to stop measles and rubella.