Measles cases are surging across Europe for a second straight year and will soon exceed the already-high number recorded in 2023, the World Health Organization warned Tuesday.

It called on countries to boost their vaccination efforts.

A total of 56,634 cases of measles and four deaths were registered during the first three months of the year in 45 of the 53 countries that make up the WHO European region, which includes Central Asia.

That is just 5,000 cases fewer than for the whole of 2023, when 61,070 cases and 13 deaths were reported in 41 countries.

It is also 60 times more than the 941 cases reported in 2022.

"Measles cases across Europe continue to surge, with the number of measles cases recorded for this year soon to exceed the total number of cases reported throughout 2023," the WHO said in a statement.

"I urge all countries to take immediate action, even where overall immunisation coverage is high, to vaccinate the vulnerable, close the immunity gaps and thereby prevent the virus from taking hold in any community," WHO Europe director Hans Kluge said.

Measles is caused by a virus and spreads easily when people breathe, cough or sneeze. It is most common in children, but can affect anyone.

Symptoms often include a rash, running nose, cough and watery eyes. Complications can be severe.

At least 95 percent of children need to be fully vaccinated against the disease in a locality to prevent outbreaks.

Almost half of the cases recorded in 2023 involved children under the age of five.

The WHO said that reflected "an accumulation of children who missed routine vaccinations against measles and other vaccine-preventable diseases during the Covid-19 pandemic, coupled with slow recovery in vaccination coverage in 2021 and 2022."

It said outbreaks had been reported in 27 of the 33 countries where the disease is considered eliminated.

Azerbaijan, Kyrgyzstan and Kazakhstan were the most affected countries, with incidence rates of 2,771.15, 2,148.66 and 1,851.01 per million between April 2023 and March 2024.

Austria was the only Western European country in the top 10, with an incidence rate of 50.90 per million.