Vaccination against measles does not only protect children from the highly contagious virus, it also prevents other infectious diseases, according to a study out Thursday that helped explain why the introduction of measles vaccines prevented many more deaths than expected decades ago.
The reason is that measles may weaken children’s immune systems for two or three years, rather than weeks or months, as previously thought, said the study published in the U.S. journal Science.
“This paper suggests that immune suppression lasts much longer than previously suspected,” study author C. Jessica Metcalf, assistant professor of ecology and evolutionary biology and public affairs at the Princeton University said in a statement.
“If you get measles, three years down the road, you could die from something that you would not die from had you not been infected with measles,” said Metcalf.
Measles vaccines were introduced 50 years ago and were followed by 30 to 50 percent reductions in child mortality in resource-poor countries and up to 90 percent reductions in the most impoverished populations.
“The observed benefits cannot be explained by the prevention of primary measles virus infections alone, and they remain a central mystery,” the paper wrote.
In the new study, Metcalf and colleagues analyzed data from before and after mass measles vaccinations began in Britain, the United States, and Denmark, the only countries with the key variables required for the analysis.
Their results suggested that measles may induce a kind of ” immune amnesia,” where essential memory cells that protect the body against infectious diseases are partially destroyed, so that the immune system forgets how to fight off a wide range of bacterial invaders.
This vulnerability was previously thought to last a month or two, but the new study revealed that this measles-induced immune damage actually remained for an average of 28 months.
During that time, individuals who have fought off the measles virus are vulnerable to a slew of opportunistic pathogens, suggesting a very strong correlation between measles incidence and deaths from other diseases.
That is why measles vaccination is so important. “Our findings suggest that measles vaccines have benefits that extend beyond just protecting against measles itself,” said lead author Michael Mina, a medical student at Emory University who worked on the study as a postdoctoral researcher at Princeton.” It is one of the most cost-effective interventions for global health.”
Immunize your child today!