Measles: the importance of vaccination, disease monitoring and surveillance

Measles infection is usually mild and self-limiting, but it can be fatal.¹ Global reduction in the incidence of, and mortality from, infectious diseases among children was one of the United Nations Millennium development goals,² and the World Health Organization (WHO) identified enhanced coverage of measles vaccination as a way to support this aim.³ During the first 15 years of the 21st century, reported incidence of measles worldwide fell by 75%, although in 2015 there were over 134,000 deaths from the disease.⁴

In 2012, elimination of measles altogether in four of the six WHO regions (including the European region) seemed a realistic aim. The WHO region of the Americas was certified as having eradiated measles in 2016. This meant that there had been no new cases of measles acquired within any of those countries locally in the preceding three years. In 2016, there were fewer than 100 reported cases of measles in the USA, and all of those patients were thought to have been infected while outside of the country.⁵ Similarly, in September 2017 it was announced that measles had been eliminated from the UK on the basis of no evidence of transmission of the virus within the country.⁶

During 2018, however, there have been outbreaks of measles in the USA attributable to local transmission and there have been over 41,000 cases of the disease in Europe.⁷ The reasons for this appear to be complex and related more to psychology than virology. It is nevertheless important for biomedical scientists to understand them as they may have implications for other vaccination programmes.