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.

The Texas Department of State Health Services reported on Friday that it was aware of 90 cases diagnosed in the last month in the South Plains area, in the north-west part of the state. At least 77 of them were reported in children and teens under 17.

In New Mexico, officials said nine people had become sick in Lea County, along the state’s eastern border with Texas.

Measles is highly contagious and can be deadly. The outbreaks come amid a rise in US anti-vaccine sentiment, including towards the measles, mumps and rubella (MMR) jab that is typically given during childhood.

Health officials in Texas say their figures are likely to be an underestimate, as some parents may not report infections or may not realise their child has the disease.

“It is troubling, because this was completely preventable,” Dr Amesh Adalja, an infectious disease physician and senior scholar at Johns Hopkins University, told CBS News, the BBC’s US news partner.

“It’s the most contagious infectious disease known to humans,” he added.

Symptoms of the highly-infectious illness include fever, cough, runny nose, eye irritation and a rash.

A measles infection can have particularly devastating complications for pregnant women and young children, including pneumonia, neurological impairment, hearing loss and death.

Survivors are at risk of developing a degenerative brain and nervous system disease known as subacute sclerosing panencephalitis (SSPE).

Most US children receive two shots to protect against the illness, which together are 97% effective in protecting against measles, according to the Centers for Disease Control and Prevention (CDC).

Health experts say that the disease could be controlled or even eradicated with proper inoculation rates – generally defined as 95% of a community receiving the vaccine.

But vaccination rates have dropped in some communities in recent decades as a loose network of vaccine sceptics have, without evidence, questioned the safety and efficacy of the shots.

Robert F Kennedy Jr, recently confirmed as US President Donald Trump’s health secretary, has faced strong criticism for his ties to these groups.

Most states require that children receive the MMR vaccine to attend school, but many, including Texas, also allow families to file a conscientious exemption – a non-medical reason to refuse a vaccine requirement.

In Texas, federal data shows that the state achieved a 94.3% vaccination rate among kindergarteners for the 2023-2024 school year, while New Mexico reached 95%.

But a state survey of Texas schools found that rates of exemptions were ticking upwards for MMR and other required vaccines.

In Gaines County, where 57 of the Texas cases were reported, exemptions have surged over the last decade. State data shows 17.62% of students had a conscientious exemption to at least one required vaccine during the 2023-2024 school year, up from 7.45% in the 2013-2014 year.

Neighbouring Terry County, home to 20 cases, saw exemption rates go from zero to 3.73% in the same time period.

Texas officials reported that of the 90 cases in their state, 85 were in people who are unvaccinated or whose vaccination status was unclear.

CBS reports that the area is home to a large Mennonite community, which typically have low vaccination rates due to the group’s religious beliefs.

Some officials are reluctant to intervene.

“We respect everyone’s right to vaccinate or not get vaccinated,” Albert Pilkington, CEO of the nearby Seminole Hospital District, told the Texas Standard. “That’s just what it means to be an American, right?”

US children have been vaccinated against measles since 1963. The jab was improved and combined with vaccines for the mumps and rubella viruses about a decade later, and is widely considered to be safe.

Prior to the vaccine’s introduction, around 48,000 people were hospitalized with measles each year and 400–500 people died. In 2024, the US reported 285 cases with 114 hospitalisations.

Health officials in New Mexico are offering a free vaccine clinic this week in an effort to boost protection. Texas also directed residents to contact their doctors or visit a clinic to get vaccinated if they have not previously received a shot.