Practices in London are to step up efforts to improve child vaccination rates amid threats of a major measles outbreak.

An outbreak could affect tens of thousands of people because of low vaccination rates, the UK Health Security Agency has warned. It warned that an outbreak could see between 40,000 and 160,000 people affected. In some parts of London, fewer than 70% of two-year-olds have received their first MMR dose. Across the UK measles is running at more than four times last year’s rates – with 128 cases reported to the end of June, 66% of these in London. In 2022 just 54 cases were reported.

Regional chief nurse Jane Clegg said: “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.”

The Royal College of GPs said stepping up vaccination rates would be a priority for practices.

Chair Professor Kamila Hawthorne said: “We need to restore momentum to the MMR programme; the UKHSA today has said there is a risk of a big outbreak in London – but there have been cases in all regions of the UK. This is really concerning, and we would urge all parents to check their children’s vaccinations are up to date, and if they’re not, to make an appointment as soon as possible.Maintaining high vaccination rates is a top priority for GPs and our teams, and as a society, we mustn’t become complacent. In 2017, the UK achieved measles elimination status, but unfortunately, this has been reversed in part by a lack of vaccination take up, and we have seen more cases of measles this year so far, than in the whole of 2022.”