The number of measles cases in the European region doubled last year to reach the highest level in 25 years, health officials say.

A joint report by the World Health Organization (WHO) and the UN children’s fund, Unicef, said children under the age of five accounted for more than 40% of the cases reported in Europe and central Asia.

“Measles is back, and it’s a wake-up call,” Hans Henri Kluge, WHO regional director for Europe, said. “Without high vaccination rates, there is no health security.”

The MMR vaccine – which immunises people against measles, mumps and rubella – is 97% effective in fighting off the dangerous virus.

Measles is a highly contagious disease which is spread by coughs and sneezes.

Common symptoms include:

• high fever
• sore, red and watery eyes
• coughing
• sneezing

The measles virus can lead to pneumonia, brain swelling and death.

The WHO/Unicef joint analysis covering 53 countries said there had been 127,350 measles cases reported in the European region in 2024 – the highest since 1997.

A total of 38 deaths had been reported up to 6 March 2025.

Measles cases, they added, had been declining since 1997, but the trend reversed in 2018-19 and cases rose significantly in 2023-24 “following a backsliding in immunisation coverage during the Covid-19 pandemic”.

“Vaccination rates in many countries are yet to return to pre-pandemic levels, increasing the risk of outbreaks,” they warned.

The European region accounted for a third of all measles cases globally in 2024, the joint analysis said. Within that area, Romania had the highest number of cases – 30,692 – followed by Kazakhstan with 28,147.

The WHO/Unicef statement concluded that measles remained “a significant global threat” and urged governments where cases were occurring to take quick action – and those where the virus had not arrived to be prepared to act.

There have been two deaths in the US recently as the disease – which was considered “eliminated” in the US in 2000 – spreads there and across Canada, too.

Falling vaccination rates have been blamed for the recent flare-up.

In Europe, for instance, eight out of 10 people who were diagnosed with measles in the last year were not vaccinated, according to data from the European Centre for Disease Prevention and Control (ECDC).

Estimates from 2023 show that only four countries – Hungary, Malta, Portugal and Slovakia – had met the 95% threshold for vaccination to prevent an outbreak, the ECDC said on Tuesday.

Concern has been expressed in the UK, too, over the spread of the disease, as vaccination rates for two doses have fallen below 90%.

Dr Ben Kasstan-Dabush of the London School of Hygiene and Tropical Medicine warned people against trusting unverified information on their social media.

“We also learnt from the Covid-19 vaccination programme that misinformation can travel rapidly and can influence people’s decisions. It’s important to be mindful that the vaccine information on social media may not be based on scientific evidence,” Dr Kasstan-Dabush said.