DHAKA — Bangladesh launched an emergency measles-rubella vaccination campaign on Sunday targeting children in 18 high-risk districts to contain an outbreak that has killed more than 100 children in less than a month. The government, working in partnership with the World Health Organization, UNICEF and the Gavi vaccine alliance, began vaccinating children aged 6 months to 5 years and will expand the effort nationwide in phases starting next month.

More than 900 cases of measles have been confirmed among 7,500 suspected cases reported since March 15, according to official data. The country's measles vaccination campaign had been disrupted during Bangladesh's recent political upheavals, and health officials have identified growing immunity gaps across the nation of more than 170 million people. "This resurgence highlights critical immunity gaps, particularly among zero-dose and under-vaccinated children, while infections among infants under nine months, who are not yet eligible for routine vaccination, are especially alarming," said Rana Flowers, UNICEF representative in Bangladesh.

Measles is a highly contagious airborne disease that causes fever, respiratory symptoms and a characteristic rash and can sometimes have severe or fatal complications, especially in young children, according to the WHO. The organization says 95% of a population must be vaccinated to prevent measles from spreading.

Authorities are advising parents to take children to hospitals whenever measles is suspected rather than seeking treatment through informal channels. F. A. Asma Khan, deputy director of the Infectious Diseases Hospital in Dhaka, emphasized the need for professional medical attention during the outbreak. "They should avoid taking medicine from shopkeepers unnecessarily," Khan said.

Bangladesh Health Minister Sardar Mohammed Sakhawat Husain attributed the outbreak to mismanagement and failures of past governments. He said the previous government of Sheikh Hasina and the interim government led by Muhammad Yunus failed to make proper decisions regarding vaccine stockpiles, causing shortages affecting measles vaccines and six other diseases. No independent public health expert or opposition response to those claims was immediately available.

Bangladesh launched a mass immunization campaign in 1979, and the coverage of fully immunized children in the country has since increased from 2% to 81.6%. Despite those gains, UNICEF warned last year that disparities persist in immunization coverage across Bangladesh.