UK officials warn low measles immunization rates could lead to tens of thousands of cases in London

Britain's Health Security Agency said on Friday that measles vaccination rates in parts of London have dropped so low that the capital could see tens of thousands of cases of the rash-causing disease unless immunization coverage is quickly boosted. In a statement, the agency said that among some groups of children in London, fewer than 70% have received their first dose of the standard measles, mumps and rubella vaccine; two doses are needed to provide protection. Measles is among the world's most infectious diseases and health experts estimate that about 95% of the population must be immunized to stop new outbreaks.