A French biotech company announced additional Phase 1 clinical trial results for its chikungunya vaccine candidate, VLA1553.

According to a new press release, the VLA1553 vaccine candidate showed an excellent immunogenicity profile in all vaccinated dose groups after a single vaccination with a 100 percent seroconversion achieved at Day 14 in all dose groups and fully sustained at 100 percent at month number six.

VLA1553 was reported by Valneva generally safe in all dose groups of the VLA1553-101 Part B study, which is a randomized, observer-blinded, multicenter, dose-escalation investigation in 120 participants.

Furthermore, the low and medium dose groups were well tolerated and showed a superior safety profile, including viremia, compared to the high dose.

And, a subset of study subjects were re-vaccinated after 6 months, who showed no anamnestic response. This demonstrated that a single vaccination of VLA1553 is sufficient to induce sustaining, high titer, neutralizing antibodies.

Vaccinees were found protected from vaccine-induced viremia, serving as "intrinsic human viral challenge. And no adverse events of special interest (e.g. chikungunya infection related) were reported up to month number seven.

This is good news since there are no preventive vaccines or effective treatments available for the Chikungunya virus.

An independent Drug Safety Monitoring Board continuously oversees this study and reviews data.

“This marks a very important milestone getting us a step closer to a highly competitively differentiated vaccine addressing a serious threat to public health," said Wolfgang Bender, M.D., Ph.D., Chief Medical Officer of Valneva.

VLA1553 was granted Fast Track designation by the U.S. Food and Drug Administration in December 2018.

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

Recent chikungunya news:

Chikungunya is a mosquito-borne viral disease caused by the Chikungunya virus (CHIKV), a Togaviridae virus, transmitted by Aedes mosquitoes.

Clinical symptoms include acute onset of fever, debilitating joint and muscle pain, headache, nausea, and rash, potentially developing into long-term, serious health impairments, says the Centers for Disease Control and Prevention (CDC).

The chikungunya virus causes clinical illness in 72-92% of infected humans around 4 to 7 days after an infected mosquito bite. Complications resulting from the disease include visual, neurological, heart and gastrointestinal manifestations; fatalities have been reported in elderly patients who are at higher risk.

As of 2017, there have been more than 1 million reported cases in the Americas and the economic impact is considered to be significant.

As of January 8, 2019, a total of 90 chikungunya virus disease cases with illness onset in 2018 have been reported from 23 U.S. states, says the CDC.

Valneva is committed to advancing its chikungunya vaccine candidate as quickly as possible and expects to be in a position to announce a plan to achieve licensure on July 9, 2019, in New York, NY.

More information is available at Valneva.