A promising weapon against measles

 What happens when measles virus meets a human cell? The viral machinery unfolds in just the right way to reveal key pieces that let it fuse itself into the host cell membrane.

Once the fusion process is complete, the host cell is a goner. It belongs to the virus now.

Scientists in the La Jolla Institute for Immunology (LJI) Center for Vaccine Innovation are working to develop new measles vaccines and therapeutics that stop this fusion process. The researchers recently harnessed an imaging technique called cryo-electron microscopy to show -- in unprecedented detail -- how a powerful antibody can neutralize the virus before it completes the fusion process.

"What's exciting about this study is that we've captured snapshots of the fusion process in action," explains LJI Professor, President and CEO Erica Ollmann Saphire, Ph.D., who co-led the Science study with Matteo Porotto, Ph.D., Professor of Viral Molecular Pathogenesis (in Pediatrics) at Columbia University. "The series of images is like a flip book where we see snapshots along the way of the fusion protein unfolding, but then we see the antibody locking it together before it can complete the last stage in the fusion process. We think other antibodies against other viruses will do the same thing but have not been imaged like this before."

Indeed this work may prove important beyond measles. Measles virus is just one member of the larger paramyxovirus family, which also includes the deadly Nipah virus. Nipah virus is known for being less contagious but causing a much higher mortality rate than measles.

"What we learn about the fusion process can be medically relevant for Nipah, parainfluenza viruses, and Hendra virus," says study first author and LJI Postdoctoral Researcher Dawid Zyla, Ph.D. "These are all viruses with pandemic potential."

The urgent need for measles treatments

Measles is a highly contagious, airborne disease that tends to strike children the hardest. Despite extensive vaccine efforts, the virus remains a major health threat. According to the World Health Organization and the U.S. Centers for Disease Control, measles caused around 136,000 deaths globally in 2022, with recent outbreaks in over a dozen U.S. states. The victims were mostly children under age five who were unvaccinated or undervaccinated.

"Measles causes more childhood deaths than any other vaccine-preventable disease, and it's also one of the most infectious viruses known," says Saphire.

It's not just young children at risk, explains Zyla. "The current vaccine works well, but it cannot be taken by pregnant people or people with compromised immune systems," Zyla says.

There is no specific treatment for measles, so researchers are looking for antibodies to use as an emergency treatment to prevent severe disease.

Source: ScienceDaily