Researchers have identified two antibodies that can protect animals from diseases caused by alphaviruses, which are RNA viruses mostly transmitted from mosquitoes to humans. Their findings could pave the way towards a 'universal' vaccine. The study was published in Cell.
While alphaviruses have previously been limited to the tropics, in recent years, they have been found in other regions too. While relatively uncommon, they are responsible for millions of infections around the world. In the US, this includes the chikungunya virus, which can cause a debilitating form of arthritis, as well as the Eastern equine encephalitis virus, causing encephalitis or a brain infection.
For the current research, scientists screened a set of antibodies produced by two people who had been infected by the chikungunya virus. They then tested their antibodies against a set of alphaviruses in cell lines, including those that cause fever, rash, arthritis, and encephalitis. In doing so, they found that two of the antibodies recognized all of the alphaviruses tested.
The researchers then tested the antibodies out on mice. The two antibodies could also protect mice from two alphaviruses that cause arthritis and three that cause brain infections.
Later experiments found that the antibodies worked by attaching to a part of a viral protein called E1 that is exposed only during the exiting process. In doing so, it prevented the virus from exiting cells and infecting others.
“If we could figure out how to make a vaccine that targets the E1 protein effectively, it would be a cost-effective way to provide broad protection for people in resource-limited places, which is where most alphavirus infections occur,” said Michael S. Diamond, senior author of the paper
“It’s challenging to make such a vaccine since the target is hidden most of the time. But there are techniques that can be used to make the immune system focus on E1 and generate a good antibody response against it. That’s the next step toward creating a universal vaccine.”