Scientists claim that delayed appearance of IgG3 antibodies (a naturally-acquired antibody) serves as a specific biomarker that increases the risk of the more severe form of Chikungunya.

With the help of computational experts from A*STAR's Institute for Infocomm Research (I2R), the team also found that a very small defined segment of the Chikungunya viral protein, named E2EP3, was able to induce the natural IgG3 protective response in pre-clinical models.
Chikungunya is a mosquito-borne infectious disease endemic to Southeast Asia and Africa. There is no clinically-approved vaccine or treatment for chikungunya. It is characterised by persistent joint pain that lingers for months. Most patients recover within a week but immunocompromised patients may succumb to the disease.
Source-Medindia