Table 1. CHIKF vaccines in late preclinical or clinical development.

Vaccine name	Developer	Vaccine type	Doses required/tested	Current stage of testing (clinicaltrials.gov identifier)	References
TSI-GSD-218 (181/clone25)	United States Army Medical Research Institute of Infectious Diseases, University of Maryland	Live-attenuated CHIKV strain	1	Completed Phase 2	[32, 33]
VRC-CHKVLP059-00-VP (PXVX0317 CHIKV-VLP)	US National Institutes of Health, PaxVax	Virus-like particle assembled from CHIKV proteins expressed in mammalian cells	2	Phase 2 (NCT02562482, NCT01489358, NCT03483961)	[49, 50]
MV-CHIK	Inst. Pasteur, Themis Bioscience	Recombinant live- attenuated measles vaccine expressing CHIKV virus-like particles derived from the structural protein genes	2	Phase 2 (NCT03101111, NCT02861586)	[44, 63]
VLA1553	Valneva, Austria	Recombinant CHIKV with nsP3 deletion	1	Recruiting for Phase 1 (NCT03382964)	[38, 64]
VAL-181388	Moderna Therapeutics	mRNA encoding the CHIKV structural proteins	Not reported	Recruiting for Phase 1 (NCT03325075)
pMCE321	University of Pennsylvania, Philadelphia	Structural protein genes E3, E2, and E1 linked in a single DNA construct with furin cleavage sites between them	3	Late preclinical (immunogenicity and efficacy in mice, immunogenicity in NHPs)	[58]
CHIKV/IRES	University of Texas Medical Branch, Takeda Pharmaceuticals	Recombinant CHIKV with subgenomic promoter replaced by internal ribosome entry site to down-regulate structural proteins and prevent mosquito infection	1	Late preclinical (immunogenicity and efficacy in mice, NHPs)	[41–43]
EILV/CHIKV	University of Texas Medical Branch	Recombinant Eilat/chikungunya chimeric virus that is replication-defective in vertebrate cells	1	Late preclinical (immunogenicity and efficacy in mice, NHPs)	[48]

Abbreviations: CHIKF, chikungunya fever; CHIKV, chikungunya virus; EILV, Eilat virus; NHP, nonhuman primate; nsP3, nonstructural protein 3.