A virus-like particle vaccine for epidemic Chikungunya virus protects nonhuman primates against infection

Abstract

Chikungunya virus (CHIKV) is an emerging infectious agent that can cause severe disease in humans and against which there is presently no vaccine. Akahata et al. now describe their development of a virus-like particle (VLP) vaccine that elicits neutralizing antibodies against CHIKV and can protect nonhuman primates from infection. Their VLP-based approach may facilitate development of a CHIKV vaccine for human use. Chikungunya virus (CHIKV) has infected millions of people in Africa, Europe and Asia1,2 since this alphavirus reemerged from Kenya in 2004. The severity of the disease and the spread of this epidemic virus present a serious public health threat in the absence of vaccines or antiviral therapies. Here, we describe a new vaccine that protects against CHIKV infection of nonhuman primates. We show that selective expression of viral structural proteins gives rise to virus-like particles (VLPs) in vitro that resemble replication-competent alphaviruses. Immunization with these VLPs elicited neutralizing antibodies against envelope proteins from alternative CHIKV strains. Monkeys immunized with VLPs produced high-titer neutralizing antibodies that protected against viremia after high-dose challenge. We transferred these antibodies into immunodeficient mice, where they protected against subsequent lethal CHIKV challenge, indicating a humoral mechanism of protection. Immunization with alphavirus VLP vaccines represents a strategy to contain the spread of CHIKV and related pathogenic viruses in humans.