Professor Heidi Larson, the director of the Vaccine Confidence Project at the London School of Hygiene and Tropical Medicine, said some countries are “scrambling” to vaccinate too late.
She said: “Despite an available, safe and effective measles vaccine, not enough people are being vaccinated to prevent this devastating loss of life.
“Some countries are scrambling to vaccinate in the face of serious outbreaks, far too late for many.
“Stressed systems due to multiple disease outbreaks, conflict, rumours and distrust contribute to the measles crisis.”