Measles Wipes Out Immune System's Memory, Bigger Threat Than Thought; Study

The Guardian, Oct. 31, '19. Measles wipes out immune system's memory, study finds. Scientists say threat posed by measles is ‘much greater than we previously imagined.’

Measles causes long-term damage to the immune system, leaving children who have had it vulnerable to other infections long after the initial illness has passed, research has revealed. Two studies of unvaccinated children in an Orthodox Protestant community in the Netherlands found that measles wipes out the immune system’s memory of previous illnesses, returning it to a more baby-like state, and also leaves the body less equipped to fight off new infections.

Measles eliminated between 11% and 73% of children’s protective antibodies, the research found.

“We’ve found really strong evidence that the measles virus is actually destroying the immune system,” said Prof Stephen Elledge, a geneticist at Harvard Medical School and co-author of one of the papers. “The threat measles poses to people is much greater than we previously imagined.”

Globally, measles affects more than 7 million people each year and causes more than 100,000 deaths. Reduced vaccination rates have led to a nearly 300% increase in measles infections since 2018.

The UK recently lost its measles-free status because of the fall in rates of MMR (measles, mumps and rubella) immunisation. Coverage of 95% of the population is considered necessary to prevent outbreaks. Among children aged 24 months in England, vaccination dropped from 91.2% in 2017-18 to 90.3% in 2018-19, the lowest rate since 2010.

Measles is highly contagious and can be spread when someone with the virus coughs, sneezes or exhales. Once inside the respiratory tract, the virus penetrates immune cells that sit at the interface between the lungs and bloodstream. From there, the virus replicates and spreads to immune cells throughout the body.

Previously, scientists had inferred a longer-term impact on the immune system because deaths from other infections were seen to go up after a measles outbreak, and because the virus directly attacks the immune system. The latest work for the first time uncovers the extent of the damage...

More, https://www.theguardian.com/science/2019/oct/31/measles-wipes-out-immune-systems-memory-study-finds