Press release

London at risk of measles outbreaks with modelling estimating tens of thousands of cases

UKHSA modelling suggests that, unless MMR vaccination rates improve, London could see a measles outbreak with tens of thousands of cases.

Outside London the risk of large measles outbreaks is low but we could see smaller outbreaks in specific populations, including teenagers, young people and under vaccinated communities.

Those who have never received a measles vaccine (MMR) are at risk.

MMR is part of the NHS Routine Childhood Immunisation Programme. Parents whose infants missed out, or anyone of any age unvaccinated, are urged to come forward.

Susceptibility is particularly high among 19 to 25 year olds, affected by unfounded stories in the early 2000s (‘Wakefield cohorts’) and some may still not be fully vaccinated.

As part of continued efforts to protect people against getting measles, the NHS is today launching a campaign encouraging people to check their vaccination status, with targeted outreach to groups in London.

Data published today by the UK Health Security Agency (UKHSA) shows there has been a steady rise in measles cases this year. A new risk assessment also reveals the potential for a measles resurgence, particularly in London.

Between 1 January and 30 June this year there have been 128 cases of measles, compared to 54 cases in the whole of 2022, with 66 per cent of the cases detected in London although cases have been seen in all regions.

The UKHSA assessment finds the risk of a measles epidemic across the UK is considered low. However, with lower current levels of coverage in London, a measles outbreak of between 40,000 and 160,000 cases could occur in the capital.

The assessment also concludes that there is a high risk of cases linked to overseas travel leading to outbreaks in specific population groups such as young people and under-vaccinated communities.

The risk in London is primarily due to low vaccination rates over several years, further impacted by the COVID-19 pandemic, particularly in some areas and groups where coverage of the first MMR dose at 2 years of age is as low as 69.5%.

Parents should check their children are fully vaccinated with 2 MMR doses, which gives 99% life-long protection, by checking their red book or with their GP practice, which younger and older adults can also do. Anyone not up-to-date should make an appointment as soon as possible.

Achieving high vaccination coverage across the population, ‘herd immunity’, is important as it indirectly helps protect very young infants (under one) and other vulnerable groups.

It’s vital all children and adults catch up on any missed vaccinations and this is especially important if travelling overseas this summer.

Dr Vanessa Saliba, UKHSA Consultant Epidemiologist said:

Measles can be a serious infection that can lead to complications especially in young children and those with weakened immune systems. Due to longstanding sub-optimal vaccine uptake there is now a very real risk of seeing big outbreaks in London.

Measles spreads very easily but is preventable. To help protect ourselves, our families and those around us it is vital we all ensure we are vaccinated with 2 doses of the MMR vaccine, free on the NHS whatever your age. Parents can check their children’s red book to see if they are up to date or if you’re not sure anyone can call their GP practice. It’s important everyone is fully vaccinated before travelling overseas this summer.

Nobody wants to see their child or loved ones sick with measles, or put others who are more vulnerable, like babies, at risk. I urge those who have missed their MMR vaccines to catch-up now.

NHS England has launched a targeted national campaign to encourage uptake of the MMR vaccine, including targeted outreach work in London for those identified as at high risk and communities with the lowest uptake of vaccination.

This follows a polio and MMR catch-up campaign already targeting un-or-partially-vaccinated children aged 1 to 11 years in London, rolled out at the end of March through GP practices, primary schools and community vaccination clinics.

All children at primary school who have missed one or both doses of the MMR vaccine are being offered the opportunity to get up to date at school. Parents of those children will be contacted by the NHS school immunisation service. Parents of younger children or those who are home-schooled can make an appointment with their GP practice or visit a community clinic.

Jane Clegg, Regional Chief Nurse for the NHS in London said:

Measles can easily spread between unvaccinated people and can be serious, but it is preventable, which is why we continue to encourage Londoners to take up the vaccine – with GPs calling over 10,000 parents of unvaccinated children, and hundreds booking appointments to get vaccinated as a result.

Cases of measles in the capital remain low but it’s really important that people check that they, and their children, are up to date with their jabs and protected against MMR – and if you have any questions or concerns, please get in touch with your GP practice or local pharmacist for advice. Now’s the time to act to protect yourself and loved ones from measles.

Current MMR vaccine coverage in the NHS routine childhood programme is the lowest it has been in a decade. The WHO 95% vaccine coverage target is set to prevent outbreaks among populations. In England coverage of 2 MMR doses at age 5 years is around 85%, with about 10% of children in the country left unprotected from measles by the time they are ready to start school, with the rate in London at about 20%.

UK Health Security Agency press office

Nobel House
17 Smith Square


Published 14 July 2023
Last updated 14 July 2023 + show all updates
  1. First published.