Valneva’s chikungunya vaccine candidate, VLA1553, has shown promising 12-month antibody persistence results after a single-dose, the vaccine company reported.
Chikungunya is a mosquito-borne viral disease which often causes sudden large outbreaks with high attack rates, affecting one-third to three-quarters of the population in areas where the virus is circulating.
Infection leads to symptomatic disease in up to 97% of people after three to seven days following the mosquito bite, with clinical symptoms including acute onset of fever, debilitating joint and muscle pain, headache, nausea, rash and chronic arthralgia.
There are no preventive vaccines or effective treatments currently available for chikungunya and, as such, the virus is considered to be a major public health threat.
A dedicated antibody persistence trial, VLA1553-303, was set up by Valneva to confirm the anticipated long-term durability of the antibody response after a single vaccination, following positive immunogenicity and safety data from the phase 3 VLA1553-301 study in March 2022, in which a seroresponse rate of 96% six months after vaccination was reported.
The trial, which will monitor antibody persistence on an annual basis for at least five years, demonstrated 99% of participants retained neutralising antibody levels above the seroresponse threshold of 150 12 months after the single-dose vaccination.
Moreover, the antibody persistence was similar in older adults aged 65 years and over, who retained neutralising antibody levels comparable to younger adults throughout the follow-up.
No safety concerns were identified for the duration of the study, the company said, confirming the safety profile observed in previous studies.
Commenting on the positive results, Juan Carlos Jaramillo, chief medical officer of Valneva, said: “We are excited about these 12-month data which are in line with what we saw from our previous read out at month six, and strengthen the possibilities of inducing a long-lasting antibody response with our chikungunya vaccine candidate.”
The company said it expects to finalise its Biologics Licence Application (BLA) submission with the US Food and Drug Administration by the end of 2022, and make additional regulatory submissions for VLA1553 in 2023.
“We are looking forward to completing the BLA rolling submission to the FDA and potentially to changing people’s lives. If our investigational vaccine is approved, we are confident that it can help address this major, growing and unmet public health threat,” Jaramillo said.