Chikungunya is considered to be a major public health threat by the World Health Organization. A speciality vaccine company based in France on 2 June 2020 announced the publication of full data from the Phase 1 clinical trial of its chikungunya vaccine candidate, VLA1553.

A recent study showed that a single dose of vaccination is sufficient to induce sustaining high-titer neutralizing antibodies.  Vaccination with VLA1553 indicated the absence of an anamnestic response after any revaccination ranging up to 100 percent of participants. Following revaccination with VLA1553, vaccinees were protected from vaccine-induced viremia.

Successful Phase 2 results were reported to the US FDA earlier by Valneva. VLA1553 was granted Fast Track designation by the U.S. FDA in December 2018. Wolfgang Bender, Ph.D., M.D., Chief Medical Officer of Valneva is now is ready to initiate Phase 3 clinical studies in the USA later this year. 

VLA1553 is based on an infectious clone (CHIKV LR2006-OPY1) attenuated by deleting a major part of the gene encoding the non-structural replicase complex protein nsP3, aiming for protection against various Chikungunya virus outbreak phylogroups and strains.

The vaccine candidate is designed for prophylactic, active, single-dose immunization against chikungunya in humans over one year old. The VLA1553 vaccine targets long-lasting protection and an anticipated safety profile similar to licensed vaccines for active immunization in adults and children.