According to the World Health Organization, an estimated 10.3 million people were infected with measles in 2023 and 107,500 died. Most were unvaccinated people or children younger than five. Cases were most common in parts of Africa, the Middle East and Asia where incomes are low and health services insufficient.

The United States has registered its first death from measles since 2015, after a child who wasn’t vaccinated died in an outbreak in rural West Texas. Normally, most US cases are brought into the country by people who have travelled overseas.