20 million children worldwide – more than 1 in 10 – missed out on lifesaving vaccines such as measles, diphtheria and tetanus in 2018, according to new data from WHO and UNICEF. Most unvaccinated children live in the poorest countries and are disproportionately in fragile or conflict-affected states.

Since 2010, vaccination coverage with three doses of diphtheria, tetanus and pertussis (DTP3) and one dose of the measles vaccine has stalled at around 8%. While high, this is not sufficient: 95%coverage is needed – globally, across countries, and communities – to protect against outbreaks of vaccine-preventable diseases.

In 2018, almost 350,000 measles cases were reported globally, more than doubling from 2017. Ukraine leads a varied list of countries with the highest reported incidence rate of measles in 2018. While the country has now managed to vaccinate over 90% of its infants, coverage had been low for several years, leaving a large number of older children and adults at risk.

Several other countries with high incidence and high coverage have significant groups of people who have missed the measles vaccine in the past. This shows how low coverage over time or discrete communities of unvaccinated people can spark deadly outbreaks. The full press release from the WHO can be found here.