Scientists have made significant progress in the fight against measles, developing new vaccines that promise to eradicate the disease forever.
American scientists have discovered how a modified antibody (antibodies that defend cells against pathogens or infectious particles by modifying any biological effect they carry, and these particles lose their ability to infect or cause disease) can prevent the highly contagious virus.
They explained that when the measles virus meets a human cell, the viral mechanism becomes clear, revealing the main parts that allow it to integrate itself into the host cell membrane. Once the fusion process is complete, the human cell becomes "killed" and belongs to the virus.
Scientists at the La Jolla Institute for Immunology (LJI) in California have been developing new measles vaccines and treatments that stop this integration process.
It is known that measles is a highly contagious disease transmitted through the air, and it affects children more than others. Despite extensive vaccine efforts, the virus still poses a major health threat.
Measles killed an estimated 136,000 people worldwide in 2022, with most victims being children under five who were either unvaccinated or under-vaccinated.
“Measles causes more deaths in children than any other vaccine-preventable disease, and is one of the most contagious viruses known,” Professor Saphir said.
Dr. Zila added: “The current vaccine works well, but it cannot be taken by pregnant women or those with weak immune systems.”
There is no specific treatment for measles, so scientists are looking for antibodies to use as an emergency treatment to prevent severe disease.
The team of scientists recently used an imaging technique called cryo-electron microscopy to give a detailed picture of how a powerful antibody neutralizes the virus before it completes the integration process.
“What’s exciting about this study is that we’ve captured snapshots of the fusion process in action,” said Professor Erica Ullman-Safier of the La Jolla Institute for Immunology. “The series of images is like a folded book where we see snapshots of the entire process of deploying the fusion protein, but then we see the antibody binding it together before it can complete the final stage of the fusion process.”
"We think other antibodies against other viruses will do the same thing but they haven't been imaged in this way before," she continued.
The research team says their "promising" discovery, published in the journal Science, could be important beyond measles because it is just one member of the larger Paramyxovirus family, which also includes the deadly Nipah virus.
“What we learned about the fusion process could be medically relevant to Nipah viruses, human parainfluenza viruses, and Hendra virus,” said the study’s first author, Dr. Dawood Zila, a postdoctoral researcher at the La Jolla Institute for Immunology. “They are all viruses with pandemic potential.”
To better understand how measles virus fuses with cells, the research team turned to an antibody called mAb 77. They found that mAb 77 targets the measles glycoprotein, part of the viral machinery measles uses to enter human cells, through a specialized process called fusion.
The scientists investigated exactly how the antibody combats the virus. They found that mAb 77 stops the virus in the middle of the fusion process.
Now that they know how mAb 77 works, the research team hopes the antibody can be used as part of a therapeutic "cocktail" to protect people from measles or to treat patients with active measles infection.
In a follow-up trial, results showed that mAb 77 provided “significant” protection against measles in mouse models of measles infection.
The team is now seeking to study different antibodies against measles. “We would like to stop the fusion at different stages of the process and look for other therapeutic opportunities,” says Dr. Zila.