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The UK Health Security Agency (UKHSA) says that measles outbreaks continue across the UK. In England, 109 cases of measles were confirmed in April, and 86 so far in May. In total 420 cases have been confirmed since 1 January 2025.

There has also been a global increase in measles cases over the last year. The World Health Organization (WHO) reported 127,350 measles cases in the European Region, including France, Italy, Spain and Germany, for 2024, double the number of cases reported for 2023 and the highest number since 1997. The WHO reported that Romania, Pakistan, India, Thailand, Indonesia, and Nigeria have among the largest number of measles cases worldwide.

The UKHSA is concerned that there may be more outbreaks this summer as families with unvaccinated children and adults travel abroad to affected countries. This, in turn, could lead to another surge of measles cases across the UK.

Why cases of measles are growing

A decline in immunisation rates is partly to blame for the disease's growth, with only 89% of children aged 2 in England having received the first dose of the MMR vaccine, and 84% completing the recommended two doses by the age of 5 - the lowest levels since 2009-2020. These rates are short of the World Health Organization's (WHO) target of 95% coverage, which the body says is necessary to achieve and maintain elimination of the disease.

London has the lowest MMR uptake rates compared with other English regions with MMR2 uptake at 5 years just 73.3%. From Autumn 2023 to summer 2024, England experienced the biggest outbreak of measles since 2012, particularly affecting young children. Since the peak last year cases have declined but local outbreaks continue.

Measles vaccinations

The UKHSA says it is important that if you are travelling abroad, especially if you are the parents of young children, you check that all members of your family have received both their MMR vaccines.

Dr Vanessa Saliba, Consultant Epidemiologist at the UK Health Security Agency, said: “Measles spreads very easily and can be a nasty disease, leading to complications like ear and chest infections and inflammation of the brain with some children tragically ending up in hospital and suffering life-long consequences. Nobody wants this for their child and it’s not something you want to experience when away on holiday.

The MMR vaccine is the best way to protect yourself and your family from measles. It is never too late to catch up, if you’re not sure if any of your family are up to date, check their Red Book or contact your GP practice. Don’t put it off and regret it later.”

Symptoms of measles

Rougeole is caused by a highly contagious virus spread by coughing and sneezing, close personal contact, or direct contact with infected nasal or throat secretions.

The virus infects the respiratory tract then spreads throughout the body. It can be transmitted by an infected person from 4 days before to 4 days after a rash appears. The measles virus can stay active and contagious in the air or on infected surfaces for up to two hours.

The first sign of measles is usually a high fever, which can begin anywhere from 7 to 21 days after exposure to the virus - although 10-12 days is most common - and lasts 4 to 7 days. The other symptoms at the early stage include:

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• Red and watery eyes.

• Small white spots inside the cheeks can develop in the initial stage.

After several days, a rash erupts, usually on the face and upper neck. Over about 3 days, the rash spreads, eventually reaching the hands and feet. The rash lasts for 5 to 6 days, and then fades. On average, the rash happens 14 days after exposure to the virus - within a range of 7 to 18 days.

Is the MMR vaccine safe?

"Unlike the diseases they prevent, vaccines are very safe," says Dr Patrick O'Connor, a measles specialist at the WHO.

He points out that the measles vaccine continues to be highly effective. In the majority of cases, two doses given at the appropriate times provide full protection for at least several decades of life.

So why are some parents so wary of allowing their children to be vaccinated?

GP Dr Clare Morrison, explains: "Discredited research suggesting a link between the vaccin contre la rougeole, les oreillons et la rubéole (ROR) et autisme caused many parents to decide against having their child vaccinated". She says that some of this mistrust still continues today, despite official NHS advice, and education from health visitors and doctors.

"Measles is most common amongst children, and those who haven't been vaccinated are the most at risk. This includes babies who haven't yet had the routine MMR vaccination."

Potential complications of measles

According to O'Connor, anyone with measles can develop serious and even fatal complications, but complications are more common in children under the age of 5 years or adults over the age of 30.

The most serious complications of measles include:

• Loss of vision.

• Encéphalite - an infection that causes brain swelling.

• Severe diarrhoea and related dehydration.

• Ear infections.

• Severe respiratory infections such as pneumonie.

Connor says: "No specific antiviral treatment exists for measles virus. However, severe complications from measles can be avoided through supportive care that ensures good nutrition, adequate fluid intake and treatment of dehydration. Antibiotiques should be prescribed to treat eye and ear infections, and pneumonia."

The herd immunity myth

Measles is highly contagious, and will spread wherever there is a cluster of susceptible people. Morrison warns against complacency:

"Some parents rely on 'herd immunity' - the fact that most other people are immune, and that therefore the risk of contact is relatively low. However, you only need a few people to be unvaccinated for a mini-epidemic to start, or the child might come across the infection while travelling abroad."