Infectious Chikungunya Virus with a Complete Capsid Deletion: a New Approach for CHIKV Vaccine.

Zhang, Ya-Nan; Deng, Cheng-Lin; Li, Jia-Qi; Li, Na; Zhang, Qiu-Yan; Ye, Han-Qing; Yuan, Zhi-Ming; Zhang, Bo

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes epidemics of debilitating disease worldwide. Currently, there are no licensed vaccines or antivirals available against CHIKV infection. In this study, we generated a novel live attenuated vaccine (LAV) candidate of CHIKV with a complete deficiency of capsid (ΔC-CHIKV). It could propagate in BHK-21 cells, and had similar antigenic properties as native CHIKV. Vaccination of either immunocompromised IFNAR-/- mice or immunocompetent C57BL/6 mice with a single dose of ΔC-CHIKV conferred complete protection upon challenge with wild type (WT) CHIKV. Taken together, this vaccine candidate appeared to be safe and efficacious, representing a novel strategy for CHIKV vaccine design.IMPORTANTCurrently, there is no licensed vaccine against CHIKV infection. An ideal CHIKV vaccine should generate an optimal balance between efficacy and safety. Live attenuated vaccine that can elicit strong immune responses often involve a trade-off of reduced safety. Here, a novel live attenuated vaccine candidate of CHIKV lacking the entire capsid gene, ΔC-CHIKV, was developed. It was demonstrated to be genetically stable, highly attenuated, immunogenic and able to confer complete protection against lethal CHIKV challenge after a single dose of immunization. Such infectious vaccine candidate devoid of capsid provided a novel strategy for the development of live attenuated CHIKV vaccine.