The single-shot chikungunya vaccine was shown to be safe and effective against mosquito-transmitted chikungunya disease in a published analysis of Phase III results.
Valneva chikungunya vaccine shows positive results.
France-based biologics company Valneva will be advancing toward U.S. Food and Drug Administration accelerated approval of its specialty vaccine, VLA1553. The single-shot chikungunya vaccine was shown to be safe and effective against mosquito-transmitted chikungunya disease in a published analysis of Phase III results.
VLA1553 was formulated by deleting a portion of the chikungunya virus genome, meaning a successful transmission of the virus would no longer be possible. As explained by Valneva’s chief medical officer, Juan Carlos Jaramillo, M.D, “Delivering these first-ever final Phase 3 results for a chikungunya vaccine candidate means that we are a step closer to addressing a major, growing and unmet public health threat.” The study, NCT04546724, was randomized and double-blinded. Sites were erected in 44 sites across the U.S. Patients included 4,115 adults over 18 years of age, extending up to elderly participants.
Results of Valneva Chikungunya Vaccine
The results are impressive - showing 98.9% seroprotection one month after inoculation. Six months after inoculation, the protection level dropped slightly to 96.3%. These numbers exceed the FDA’s expectation of 70% protection, per the agreement to accelerate the much-needed vaccine. This candidate was given Breakthrough Therapy Designation in 2021 by the FDA and PRIME designation by the European Medicines Agency (EMA) in 2020. Each of these designations underscores the unmet need for a chikungunya virus vaccine. Side effects of the chikungunya vaccine were mild, as approximately 50% of subjects experienced a headache or general fatigue, demonstrating a high tolerability drug profile.
The primary endpoint was set to determine patient safety and seroprotection one month after the intramuscular administration. Successful secondary endpoints evaluated protection levels after six months. VLA1553-301 will be followed by a longer-term study with a subset of subjects from the original study. The continuation study, VLA1553-303, will monitor antibody resistance for up to five years after a single inoculation.
To understand the importance of the potential approval of the first chikungunya vaccine to protect against the chikungunya virus, it is important to look at the exponential increase that has been seen in chikungunya infections. Transmission is high due to being carried by a mosquito vector. Cases reached over 3 million in North and South America in 2020 but are seen as far as Southeast Asia and Africa. Outbreaks are often severe and few escape infections in the areas experiencing flare-ups.
Transmission of the chikungunya virus typically accompanies a rash of debilitating symptoms, such as joint stiffness, muscle aches, gastroenteric symptoms and a fever. Only a small fraction of infected individuals, 8%- 28%, are spared experiencing a symptomatic progression of disease. Treatment of those experiencing symptoms places an undue hardship on families and national economies alike.
Distribution and manufacturing agreements are in place to ensure that an approved chikungunya vaccine (VLA1553) is accessible to whomever needs it, despite income or location. One of these is with the Coalition for Epidemic Preparedness Innovations (CEPI) in Brazil.
The data published by Valneva, detailing all successful endpoints that have been met, is scientifically reassuring for those living in the 120 countries affected by the Chikungunya Virus. Valneva is expected to continue toward FDA approval in Q2 of 2022.
