The mosquito-borne Chikungunya virus causes fever, swelling, muscle pain, and joint pain, with some patients developing severe and debilitating arthritis that can persist for years after infection. Although most Chikungunya virus infections are not fatal, hundreds of thousands of cases occur annually in Africa and Asia, and a 2015 epidemic spread to the Americas. No approved treatments or vaccines exist for Chikungunya virus infection, but monoclonal antibodies (mAbs) have shown promise as antiviral therapeutics.

In a study published online on November 7 in PLOS Pathogens, corresponding author Jonathan Lai, Ph.D., and colleagues isolated and characterized 46 new human mAbs from two patients who contracted Chikungunya virus in the Dominican Republic. The new mAbs bound to a variety of targets within E1 and E2, the two glycoprotein subunits that decorate the surface of the Chikungunya virus. (Previous studies had harvested fewer mAbs, which targeted only the E2 subunit). Two of the E2-targeting mAbs described in the PLOS Pathogens paper successfully protected mice from a lethal challenge of Chikungunya virus.

The two protective mAbs have potential for treating arthritis caused by Chikungunya virus infection, provided they can penetrate joints. The mAbs may also be able to prevent Chikungunya virus infection—in regions where the virus is endemic and for people traveling to endemic areas. Further testing in larger animals will be needed to fully assess the mAbs’ therapeutic potential. Dr. Lai is a professor of biochemistry at Einstein.