Measles cases rose 20% last year, driven by a lack of vaccine coverage in the world's poorest countries and those riddled with conflict, the World Health Organization and the U.S. Centers for Disease Control and Prevention (CDC) said on Thursday. Nearly half of all the large and disruptive outbreaks occurred in the African region where the number of deaths increased by 37%, WHO said. Immunization coverage was "inadequate" globally, the WHO and the CDC said. About 10.3 million cases of the highly contagious infection were reported in 2023, compared with 8.65 million reported in the previous year, a report by the two agencies showed.