Measles has dominated conversations of late, in lieu of outbreaks sweeping Europe. In the first half of this year, 90,000 cases were reported, which was already more than those recorded in the whole of 2018 (84,462 cases).
The UK has become one of four European countries to lose its measles elimination status, and figures show uptake for the Measles Mumps and Rubella (MMR) vaccine has dropped for the fourth year in a row. Coverage for the vaccine is now at 91.2%, the lowest it has been since 2011-12.
The immediate consequences of measles are widely known – sufferers experience cold-like symptoms followed by a red-brown blotchy rash. And for some, the viral infection can be life-threatening.
But how does the illness affect the body long-term? New studies suggest it can disrupt the immune system – resetting it to a “baby-like” state.
Research from the Wellcome Sanger Institute and University of Amsterdam revealed that measles can effectively “delete” part of the immune system’s memory, creating an immune “amnesia” of sorts.
This essentially means measles resets the immune system back to a “baby-like” state, with limited ability to respond to new infections.
The study, which involved unvaccinated children before and after contracting measles, goes some way to explain why kids often catch other infectious diseases after having measles – in some children, the effect is so strong it is similar to being given “powerful immunosuppressive drugs”, researchers said.
Some children still show signs of immune suppression up to five years after having measles, they found, although they appear healthy when their white blood cell counts are measured.
Lead author Dr Velislava Petrova, from the Wellcome Sanger Institute and Cambridge University, said the study shows that “measles directly causes the loss of protection to other infectious diseases”.
Professor Colin Russell, senior author from the University of Amsterdam, added: “For the first time, we see that measles resets the immune system and it becomes more baby-like, limiting how well it can respond to new infections.”
Another study by the same team showed that a measles-like virus reduced the level of flu antibodies in ferrets that had been previously vaccinated against flu. The ferrets also had worse flu symptoms when infected with the flu virus after the measles-like infection.
In another study on the topic, from Harvard Medical School, scientists used a tool called VirScan to analyse the responses of antibodies in unvaccinated children before and after measles infection.
Researchers found the disease wiped out a range of 11-73% of the antibody repertoire in children two months after having measles, which severely compromised immune memory. This antibody depletion was not witnessed in children vaccinated against measles, mumps and rubella.
Rebuilding this collection of antibodies – originally built up over time through being exposed to illness – could take months or even years to achieve, scientists said. They also found children are more at risk of contracting other illnesses which they would have otherwise been protected against after having measles.
The results of these studies highlight the importance of vaccination against measles, said scientists. The vaccine not only prevents the virus, they said, but it can prevent the weakening of “herd immunity” to other kinds of pathogens – which is essential to ensuring some of the most vulnerable members of society don’t become seriously ill from the contagious infection.
“Our study has huge implications for vaccination and public health as we show that not only does measles vaccination protect people from measles, but also protects from other infectious diseases,” added Prof Russell.
Professor Stephen Powis, NHS medical director for England, told HuffPost UK the study provides further evidence of why our country “can’t be complacent” when it comes to measles.
“Vaccines prevent killer conditions like measles but also protect against serious and highly infectious diseases,” he said. “We need a collective effort to boost fallen uptake levels and why we must take a zero tolerance approach to anyone pushing ineffective alternatives to evidence-based jabs.”