By Stephen Beech via SWNS
The measles vaccine is more than twice as likely not to work in children born by Caesarean section, according to a new study.
Researchers found that a single dose of the vaccine is up to 2.6 times more likely to be “completely ineffective” in youngsters born by C-section, compared to those born naturally.
Failure of the vaccine means that the child’s immune system does not produce antibodies to fight against measles infection, so they remain susceptible to the disease.
The research team says it is “vital” that children born by C-section receive two doses of the measles vaccine for “robust” protection against the disease
A second measles jab was found to induce immunity against measles in C-section children.
Measles is one of the world’s most contagious diseases, spread by coughs and sneezes.
It starts with cold-like symptoms and a rash and can lead to serious complications including blindness, seizures, and death.
Before the measles vaccine was introduced in 1963, there were major measles epidemics every few years causing an estimated 2.6 million deaths each year.
But even low vaccine failure rates can significantly increase the risk of an outbreak.
Scientists say that a potential reason for the effect is linked to the development of the child’s gut microbiome – the huge collection of microbes that naturally live inside the gut.
The new study, published in the journal Nature Microbiology, was conducted by researchers at the University of Cambridge and Fudan University, China.
Joint senior author Professor Henrik Salje, of Cambridge University, said: “We’ve discovered that the way we’re born – either by C-section or natural birth – has long-term consequences on our immunity to diseases as we grow up.
“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.”
He said at least 95 percent of the population needs to be fully vaccinated to keep measles under control.
But the UK is well below that level, despite the Measles, Mumps and Rubella (MMR) vaccine being available through the NHS Routine Childhood Immunisation Programme.
An increasing number of women around the world are choosing to give birth by C-section.
In the UK a third of all births are by C-section, while in Brazil and Turkey, more than half of all children are born via that method.
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.”
The research team used data from previous studies of more than 1,500 children in Hunan, China, which included blood samples taken every few weeks from birth to the age of 12.
That allowed them to see how levels of measles antibodies in the blood change over the first few years of life, including following vaccination.
They discovered that 12 percent of children born via C-section had no immune response to their first measles vaccination, compared to just five percent of children born naturally.
The research team said that many of the children born by C-section did still mount an immune response following their first vaccination.
Two doses of the measles jab are needed for the body to mount a “long-lasting immune response” and protect against measles, say scientists.
In 2022 83 percent of the world’s children had received one dose of measles vaccine by their first birthday, according to the World Health Organization (WHO), the lowest level since 2008.
Salje added: “Vaccine hesitancy is really problematic, and measles is top of the list of diseases we’re worried about because it’s so infectious.”
