Like the AIDS virus, but faster, the measles virus attacks the immune system, according to a study published in Science Thursday. Patients are almost as vulnerable to pathogens as newborns, increasing the usefulness of vaccination.
Public health professionals have previously noted that measles vaccination campaigns reduce total child mortality. But the researchers were unsure of the biological mechanisms.
A team of researchers from Harvard, the Howard Hugues Medical Institute and Erasmus University in the Netherlands analyzed the blood of 77 measles-infected Dutch children during the country's epidemic in 2013: their blood was collected before infection and again two months later. .
The researchers used a tool developed in the United States called VirScan, which identifies all viruses that have ever infected a person and whose immune system resembles: HIV, influenza, herpes and hundreds of other viruses. When the body encounters a virus, it creates antibodies that remain and protect against future infections: it is the immune "memory".
Analyzes showed that measles eliminated between 11 and 73% of protective antibodies in children.
Measles "redefines your immune system and returns you to a more naive state," says Harpard epidemiologist Michael Mina, co-author of the study.
To return to a high level of antibodies and rebuild their defenses, "they must be reinfected by pathogens, like newborns who are at great risk in their early years," says Michael Mina.
Unlike HIV, immune defenses are weakened much faster and also rebuild faster, says the researcher.
The study, supported by monkey testing and other analysis published Thursday in Science Immunology, shows that the danger of measles exceeds the only risks related to infection.
"The virus is much more deleterious than we thought, making the vaccine even more valuable," says Stephen Elledge, a geneticist who developed the VirScan tool with colleagues.
© 2019 AFP