Diminishing rates of measles, mumps, and rubella jabs have prompted a Royal College warning over the risks to pregnant women, as the NHS raises concerns over London “lagging” behind the national uptake.

The Royal College of Paediatrics and Child Health’s immunisations lead, Dr Helen Bradford, said the falling uptake of the MMR vaccine could present a serious risk to pregnant women and their unborn children.

The warning comes as London health authorities are planning a major summer drive to improve uptake in the capital, The Independent has learned.

Documents seen by The Independent setting out NHS plans for a summer MMR campaign put the focus on social media, including approaching “influencers” to spread messages. The plans also rely on free publicity, with proposals to approach broadcast media.

Risks to increasing uptake, according to the document, included anti-vaxx sentiment towards MMR, apathy towards the vaccine, controversy meaning influencers won’t work with the NHS, and a lack of internal data.

As of December 2021, uptake of MMR for children at two years old was at 78 per cent in London, according to an internal dashboard. This is compared to 89 per cent across England.

Both figures are below the national target to have 95 per cent of children receiving two vaccines at 24 months old.

Experts warned that measles has become a major concern for the future.

In an interview with The Independent, Dr Bradford said: “Measles is incredibly infectious, much more infectious than Covid. It’s got an R number of kind of between 14 and 18 and that means that even a small decline in uptake can be enough to trigger outbreaks. You don’t need to have a massive decline, it can be just a small amount.

“We have got a group of children who may have missed out because of Covid, on top of the already sort of suboptimal uptake. But for MMR for measles control, you need to have 95 per cent sustained uptake of two doses, and we don’t get that.”

The Royal College lead said the other key concern is the risk rubella presents to pregnant women and their children.

She said: “Before Covid, there were quite significant increases in cases of measles, across Europe and in the UK. The age profile was such that it was mainly across all age groups, but there were lots of young people being affected. These are people who weren’t vaccinated 20 years ago because their parents were scared because of the Wakefield business.

“All those people who were catching measles a couple of years ago [pre-Covid] because they didn’t get MMR didn’t have protection against rubella either. It’s sort of gone away [here], but it’s not going away in the world. So a potential problem is that that age group get to child-bearing years, [and] they may travel abroad, where rubella is more prevalent.”

Rubella caught in the first three months of pregnancy, Dr Bradford said, and can lead to a baby being born with “very severe” brain damage.

Dr Chris Streather, medical director for the NHS in London, said: “It’s vital that parents ensure their children are fully protected against measles, mumps and rubella.

“The MMR vaccine is safe, quick and free as part of the NHS routine immunisation schedule – and it’s never too late to get both doses to give your child protection.

“We are urging parents to check their child’s red book or speak to their GP practice to check their records and ensure all immunisations are up to date.”