Has measles really been 'eliminated' in the UK?

"Measles eliminated in the UK for the first time," reports The Telegraph.

This and other stories in the media are based on a new World Health Organization (WHO) report confirming the UK is now one of 33 countries in Europe to have "eliminated" measles.

"Elimination" is the official term used once a country has reduced the number of cases of a disease to a low enough level to stop it spreading through the general population for at least three years.

It doesn't mean that measles has been wiped out or eradicated in the UK. In 2016 there were more than 500 cases in England and Wales. However, the disease wasn't able to spread more widely.

It also doesn't mean that children no longer need the MMR vaccination, which protects against mumps and rubella as well as measles. In fact it's vital that young children continue having the MMR vaccination to stop the number of measles cases rising again.

Read more about the MMR vaccination.

What is measles and what is the vaccination?

Measles is an infectious disease that can lead to serious complications, such as pneumonia. In rare cases it can be fatal. Anybody who has not been vaccinated and has not had measles before is at risk of catching it.

Having measles can cause cold-like symptoms such as a runny nose, sore red eyes, fever and small grey-white spots inside the cheeks. A few days after this, a red-brown rash will appear, usually starting on the head or upper neck and spreading down to the rest of the body.

Children need two doses of the MMR jab to be fully protected against measles, mumps and rubella. The first dose is usually given within a month of their first birthday. They will then be invited to have a second dose before starting school, usually at three years and four months.

How does the measles vaccination work?

The MMR vaccination works by delivering a weakened version of the measles, mumps and rubella viruses. This triggers the immune system to produce antibodies. If the person later comes into contact with one of the viruses, the immune system recognises it and produces antibodies to fight it.

The effectiveness of the MMR vaccine means that cases of measles have dropped in the UK, but there have still been several outbreaks in recent years.

The UK was on the verge of achieving "elimination" in the 1990s. However, a report published in 1998 claiming a link between the MMR vaccine and autism (which was unfounded) led to a drop in parents getting their children immunised, followed by large outbreaks of measles.

What does the WHO report show us?

The WHO report says the UK has "eliminated" measles. This means that, for the past three years, the number of cases has been low enough to stop the disease circulating around the country.

If the UK wants to keep the number of cases down – and its "elimination" status – it needs to meet its targets for MMR vaccination coverage.

Are we meeting our vaccination targets?

Recent NHS data shows that 95% of children are now having their first dose of the MMR vaccination by their fifth birthday, meeting this WHO target for the first time. This means it is far more difficult for diseases to spread because so many people are immune. However, in England:

• In 2016/17, only 87.6% of children had received both doses of the MMR by their fifth birthday. This is lower than the previous two years: 2014/15 (88.6%), 2015/16 (88.2%).
• Only 91.6% had received the first dose of MMR by their second birthday, also a decrease on the previous two years: 2014/15 (92.3%), 2015/16 (91.9%).

This drop in MMR uptake over the past few years means there is a risk that cases of measles will start to rise again, particularly in London where uptake of the vaccination is lower.

Talking about the UK's new "elimination" status for measles, Dr Mary Ramsay, head of immunisation at Public Health England, told BBC News: "This is a huge achievement and a testament to all the hard work by our health professionals in the NHS to ensure that all children and adults are fully protected with two doses of the MMR vaccine.

"We need to ensure that this is sustained going forward by maintaining and improving coverage of the MMR vaccine in children and by catching up older children and young adults who missed out."