Children born by C-section ‘at higher risk of measles as jab is less effective for some’

CHILDREN born via Caesarean are at greater risk of catching measles, a study suggests.

Around one third of women have C-sections, either planned or as an emergency.

Vaccination was 2.6 times more likely to be “completely ineffective” in C-section babies, compared to those born vaginally. 

They are therefore more susceptible to the disease. 

Children in the UK are given a dose of the MMR vaccine - for measles, mumps and rubella - at one year old and a second at three years and four months old as part of the NHS vaccine schedule.

Researchers looked at data of more than 1,500 children in Hunan, China.

They discovered that 12 per cent of children born via C-section had no immune response to their first measles vaccination, compared to just five per cent of children born naturally.

Scientists theorised why C-section babies appeared to not mount strong antibodies against the vaccine.

They said it could be linked to the development of the child's gut microbiome - the huge collection of microbes that naturally live inside the gut - which may be hampered when born via C-section.

Prof Salje said: "With a C-section birth, children aren't exposed to the mother's microbiome in the same way as with a vaginal birth.

"We think this means they take longer to catch up in developing their gut microbiome, and with it, the ability of the immune system to be primed by vaccines against diseases including measles."

A second measles jab was found to induce immunity, therefore the research team say it is "vital" that children born by C-section receive two doses for "robust" protection.

Professor Henrik Salje, of Cambridge University, said: "We know that a lot of children don't end up having their second measles jab, which is dangerous for them as individuals and for the wider population.

"Infants born by C-section are the ones we really want to be following up to make sure they get their second measles jab, because their first jab is much more likely to fail."

In the UK, less than 90 per cent of two-year-olds have had one dose, and 86 per cent of children aged five have had two doses.

Coverage of 95 per cent or more is needed for herd immunity.

But world vaccine rates for measles are the lowest since 2008.

Commenting on the study, Alastair Sutcliffe, Professor of General Paediatrics, University College London (UCL), said: “This paper applies to a population where the vaccine is given at a different age than in the UK and supports our policies of giving the vaccine when we do.

“It will be interesting to see if this observation is corroborated by work in other countries and if China changes its timing of MMR vaccine so that the risk of non response is reduced.

"Presently China has a different age at first vaccination than for example UK or USA, and because of that they have a poorer coverage of risk, however this study may cause a rethink in the public health policy regarding MMR timing.”

The UK had a surge of measles cases from October 2023, prompting health chiefs to urge parents to check their child's vaccination status.

The UK Health and Security Agency said in an update last week: "The rapid increase in cases seen in late 2023 was initially driven by a large outbreak in Birmingham but activity there has now stabilised and in more recent weeks we have seen a rise in cases in London and smaller clusters ongoing in other regions."

Since 1 October, in England there have been 1,109 laboratory confirmed measles cases.

Dr Vanessa Saliba, UKHSA Consultant Epidemiologist, said: "The MMR jab offers the best protection against measles.

"Measles is preventable but many thousands of children around the country are still not fully vaccinated and may be at risk of serious illness or life-long complications. No parent wants this for their child."