A national campaign to boost uptake of a vaccine that protects against measles has been launched in England after a rise in cases of the potentially deadly disease.

Measles outbreaks have occurred around the country, including in London, with the West Midlands experiencing cases at their highest level since the mid-1990s.

The situation has led the UK Health Security Agency (UKHSA) to declare a national incident, with health experts warning further outbreaks could occur in other towns and cities unless uptake of the measles, mumps and rubella (MMR) vaccine increases in areas at risk.

Figures from NHS England suggest more than 3.4 million children under the age of 16 years are unprotected against this trio of serious, and preventable, diseases.

The new campaign will encourage parents and carers of children aged from six to 11 to make an appointment with their child’s GP practice so they can receive missed MMR vaccinations, and just over a million people aged 11 to 25 in London and the West Midlands will also be encouraged to catch up on missed jabs.

“People who are unvaccinated can get catch-up jabs at MMR pop-ups in schools and other convenient places, while GPs, teachers and trusted community leaders are encouraging groups that are less likely to get their jab to come forward,” said Steve Russell, NHS England’s director of vaccinations and screening.

“All this builds on the national MMR catch-up campaign the NHS rolled out at the beginning of winter, with text, email and letter reminders sent out to parents and guardians of children up to five who have yet to get full protection.”

Measles is a highly infectious virus that can cause serious illness and even death in children and adults. If measles is caught during pregnancy it can lead to stillbirth, miscarriage and low birth weight.

While there is no specific treatment for measles, it can be prevented.

Experts have stressed the MMR vaccine is not only safe but highly effective, with about 99% of people protected against measles after two doses.

MMR jabs are given twice, typically at the age of one and subsequently at three years and four months. Protection against measles after two doses is lifelong.

In 2016 the UK was declared measles-free. However, that status has since been lost.

NHS data has revealed a decline in uptake of the MMR vaccine in recent years, with figures for 2022-23 showing only 84.5% of children in England had received the second MMR vaccine dose by five years of age.

However, there is considerable variation in uptake around the country, with figures as low as 74% in London, compared with 90% in the south-west.

Uptake matters for individuals and the wider community: vaccination rates of 95% would stop measles spreading completely, protecting those unable to be vaccinated, such as young babies.

It is not the first time concerns have been raised about MMR uptake. Andrew Wakefield’s now comprehensively debunked 1998 claim that the MMR jab is linked to autism led to a decline in vaccinations that left a generation of young people at increased risk of measles, mumps and rubella.

The current decline in uptake is thought to be down to a number of factors, including the influence of vaccine misinformation, some parents erroneously not considering measles to be serious, people experiencing difficulties accessing appointments, and the impact of the Covid pandemic.

The UKHSA consultant medical epidemiologist Dr Gayatri Amirthalingam said the continuing downward trend in the uptake of routine childhood vaccinations was a serious concern.

“The diseases that these vaccines protect against, such as measles, can be life-changing and even deadly. No parent wants this for their child, especially when these diseases are easily preventable,” she said.

Prof Helen Bedford of UCL Great Ormond Street Institute of Child Health welcomed the campaign.

“By targeting six- to 11-year-olds they will be targeting the age group where we are seeing most cases. In addition, 11- to 25-year-olds in areas with low uptake where we are seeing the outbreaks will also be targeted,” she said.

But, Bedford added: “It is also important to remind parents of all children, older teenagers and young adults that they too should and can be vaccinated.”