Researchers have identified "broadly neutralizing" antibodies that protect against infection by multiple, distantly related alphaviruses - including Chikungunya virus - that cause fever and debilitating joint pain. The discovery, in mice, lays the groundwork for a single vaccine or antibody-based treatment against many different alphaviruses.

They screened 60 neutralizing mouse and human antibodies against Chikungunya and determined that 10 react against three or more different alphaviruses that cause arthritis-like symptoms. They also identified a small piece of the alphavirus called an epitope that is identical across the arthritogenic alphavirus family.

In follow-up work in cell cultures, they showed that antibodies that recognize this epitope also protect against infection by multiple alphaviruses. The antibodies blocked multiple steps in the viral life cycle, including the virus's ability to enter or exit host cells.

To confirm that the antibodies could protect animals from disease, the researchers infected mice with three different alphaviruses: Chikungunya, the closely related O'nyong'nyong virus, or the more distantly related Mayaro virus. The mice then were treated with the each of two of the most potent broadly neutralizing antibodies, and both antibodies markedly reduced joint disease caused by any of the viruses.

The researchers then identified a section of an alphavirus protein as the key binding site for the cross-protective antibodies. When such an antibody binds to this site, it changes the three-dimensional structure of the proteins on the surface of the virus, thus providing an explanation for how these antibodies prevent viral infection.

https://news.wustl.edu/news/Pages/Research-points-to-development-of-single-vaccine-for-Chikungunya-related-viruses.aspx