Measles outbreaks in Britain: why are cases rising and vaccination rates falling?

With measles outbreaks happening across England and Wales, we look at what’s behind the rise and what needs to be done to stop it.

What is measles?

Measles is a highly contagious virus that can cause serious illnesses, such as encephalitis.

“Even in high-income countries such as Britain, around 1 in 5,000 die from the infection,” said Prof Helen Bedford of the UCL Great Ormond Street Institute of Child Health, adding that measles is often more serious in adults .

Measles is associated with cold symptoms and high fever, followed by a rash that usually starts on the face but can spread throughout the body.

“Aside from controlling the symptoms of measles, there is no treatment,” says Bedford.

What is the current situation?

The number of measles cases is increasing. This is evident from data from the British Health Security Agency. In 2023, there were 1,603 suspected cases in England and Wales, compared to 735 in 2022, 360 in 2021 and 695 in 2020. Before the Covid pandemic, the figures were even higher, with 2,422 suspected cases in 2019 and 2,608 in 2018, a situation which also caused alarm.

Outbreaks have occurred across England in recent months in Londonwhile the West Midlands experienced it cases at the highest level since the mid-1990s. The Children’s Hospital in Birmingham reported it had been seen more than 50 children required treatment in the past month.

Don’t we have a vaccine?

Yes, it is very effective (about 99% after two doses) and free. It is given as part of the MMR jab, with the first dose usually given at one year of age and the second at three years and four months. But teens and adults who missed it can also get vaccinated.

Vaccination rates of around 95% would give the entire population herd immunity, meaning that the few who are not vaccinated – young babies, for example – are protected because the people around them are immune to measles.

So what’s going on?

The problem is that vaccination rates in some parts of the country are not high enough to prevent the virus from spreading. Data for 2022-2023 shows that only 84.5% of children in England will receive the second dose of MMR vaccine by the age of five, while in London and Birmingham a quarter of five-year-olds have not yet had two doses of MMR .

Experts have put this down to a number of reasons, including some parents not realizing the NHS was still offering MMR vaccinations during the pandemic, not realizing how serious measles can be, having trouble getting appointments, or being influenced by anti-vaccine conspiracy theories.

One of the most influential pieces of disinformation was Andrew Wakefield’s 1998 claim that the MMR jab could be linked to autism – a theory that has since been completely debunked.

Paul Hunter, professor of medicine at the University of East Anglia, noted a 2019 British study showing that people born between 1998 and 2004 – the period after the Wakefield paper – not only most susceptible to measles, but also had the highest incidence.

However, the latest data for England shows this the majority of the 209 laboratory-confirmed cases of measles between January 1, 2023 and November 30, 2023 were in children under 10 years old, due to the decline in vaccination rates.

Are there any other factors at play?

Adam Finn, professor of paediatrics at the University of Bristol, said the closure of schools, shops and other institutions during the Covid pandemic would have reduced measles transmission. Combined with lower vaccination rates, this meant that once Covid restrictions were eased, there was a larger pool of susceptible people.

“That obviously creates a situation where you get more cases when the virus is around,” Finn said.

Where does this leave us?

In short, Britain has returned to a situation that was already bad before the pandemic.

“We’ve now seen hundreds of cases that have developed over the years,” Finn said. “I think it’s right to be concerned because it’s completely preventable.”

In 2016, Britain was even declared measles-free. But that status has not been maintained.

Hunter said with vaccination rates continuing to decline in young children, he expects measles to become an increasing problem in the coming years.

Bedford also expressed concern. “Measles is nasty: when we have large outbreaks it is inevitable that there will be deaths,” she said. “But apart from the risk to children, it will also put extra pressure on the NHS at a time when it is most under pressure.”

What needs to be done?

Experts say it is crucial to encourage parents to get their children vaccinated against measles.

But Finn added that funding was essential for a proactive approach, such as chasing people to attend appointments.

“A lot of this is just another legacy of a decade of underinvestment (in the NHS),” he said.