Measles sabotages the immune system — so it's much more dangerous than we'd realized
Measles infections can wipe our bodies' hard-earned store of antibodies against other illnesses
Outbreaks of measles around the world are on the rise, raising concerns among public health authorities that deaths from the disease could see a significant increase.
But a study released this year suggests that the mortality rate from measles is much higher than we thought it was, because it's causing deaths we didn't know it was responsible for.
"It not only kills people directly, but it does so indirectly," Stephen Elledge, told Quirks & Quarks host Bob McDonald. He was the senior author of a study that discovered a measles infection can wipe out the "memory" of our immune systems.
Elledge, a professor of genetics and medicine at the Brigham and Women's Hospital and Harvard Medical School, was working with colleagues using a new system that can detect antibodies against viruses in a drop of blood.
Antibodies are proteins that serve as the immune system's memory and recognition system for infections it has faced in the past, allowing it to fight off these infections more easily when encountered again.
They tested blood samples from Holland from unvaccinated children before and after a measles outbreak to see how their immune systems responded.
Getting the measles virus is like being in an accident for your immune system — it causes damage that can lead to 'immune amnesia.'- Stephen Elledge, Harvard Medical School
Elledge discovered that measles infection causes "immune amnesia" by wiping out 11 to 73 per cent of our bodies' antibodies.
"Not only do you have to survive the actual measles infection, which is itself very deleterious, but now you're at a disadvantage in the rest of your life with respect to battles that you previously fought and won," said Elledge.
Measles virus even more deadly than we thought
He said his findings also explain past epidemiological data that hinted the measles vaccine had a much greater protective effect than just preventing mortality due to measles.
When the measles vaccine was introduced to the United Kingdom in the early 1970s, it unsurprisingly reduced deaths directly attributed to a measles infection — saving some 400 lives. But scientists also saw an unexplained drop in childhood mortality due to other causes.
The implication was that children who had avoided getting the measles also avoided a range of other potentially lethal infections.
Elledge said his study suggests that the measles virus is attacking our immune system and can result in the deaths of "five times as many people" than measles alone.
"Getting the measles virus is like being in an accident for your immune system — it causes damage that can lead to 'immune amnesia,'" added Elledge, referring to the importance of getting vaccinated.
"The vaccine is like a seatbelt for your immune system."
