We've seen recent spikes in measles infections.
Some European countries, including the UK, lost their measles-free status and many developing countries, especially parts of Africa, Asia and Oceania are seeing frequent outbreaks, BBC reported.
Every region in the world, expect the Americas, is experiencing an increase in the number of cases of measles, a vaccine-preventable disease that can kill or disable children, the World Health Organization (WHO) said on Thursday.
The United States' worst measles outbreak in a quarter-century spread to Idaho and Virginia last week as public health authorities on Monday reported 41 new cases of the highly contagious and sometimes deadly disease.
The United States has recorded 60 new measles cases, taking confirmed cases for the year to 940, the worst outbreak since 1994 and since measles was declared eliminated in 2000, federal health officials say.