By NewsDesk  @bactiman63

Vaccine company, Valneva, announced Monday positive antibody persistence data twelve months after vaccination with a single dose of its chikungunya vaccine candidate, VLA1553.


Following positive immunogenicity and safety data for Phase 3 study VLA1553-301 in March 2022, Valneva set up a dedicated antibody persistence trial (VLA1553-303) to monitor a subset of participants for a period of at least five years and confirm the anticipated long-term durability of the antibody response after a single vaccination.

The antibody persistence trial enrolled 363 healthy adult participants and followed them from month 6 after vaccination to month 12. 99% of participants retained neutralizing antibody titers above the seroresponse threshold of 150 12 months after the single-dose vaccination.   These antibody levels confirm the antibody persistence profile observed in an earlier study. The antibody persistence was similar in older adults aged ≥65 years, who retained neutralizing antibody titers comparable to younger adults throughout the follow-up. These results follow completion of the pivotal study VLA1553-301, for which a seroresponse rate of 96% six months after vaccination1 was reported. The study will continue to monitor antibody persistence on an annual basis.

No safety concerns were identified for the duration of the follow-up study, confirming the safety profile observed in previous studies.

Juan Carlos Jaramillo M.D., Chief Medical Officer of Valneva, said, “We are excited about these twelve-month data which are in line with what we saw from our previous read out at month 6, and strengthen the possibilities of inducing a long-lasting antibody response with our chikungunya vaccine candidate. 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.”