VIF World-FDA Approves First Vaccine to Prevent Disease Caused by Chikungunya Virus

Nov. 9, 2023——The U.S. Food and Drug Administration (FDA) has given the green light to Ixchiq, the world's first chikungunya vaccine developed by Velneva, an Austrian biotech. This vaccine is now approved for individuals aged 18 and above who are at an increased risk of exposure to the chikungunya virus.

Chikungunya, primarily transmitted by infected mosquitoes, has emerged as a global health threat with over 5 million reported cases in the past 15 years. The highest risk areas are in tropical and subtropical regions of Africa, Southeast Asia, and parts of the Americas where chikungunya-carrying mosquitoes are endemic. However, the virus has expanded to new regions, increasing its global prevalence.

Typical symptoms of chikungunya include fever and joint pain, along with a rash, headache, and muscle pain. Some individuals suffer from debilitating joint pain that can last for months or even years. Standard treatment involves rest, hydration, and over-the-counter pain and fever medications.

"Infection with the chikungunya virus can lead to severe disease and long-term health issues, especially for older adults and individuals with underlying medical conditions," stated Dr. Peter Marks, Director of the FDA's Center for Biologics Evaluation and Research. "Today's approval fills an unmet medical need and represents a significant advance in preventing a potentially debilitating disease with limited treatment options."

Ixchiq is administered as a single dose via injection into the muscle. It contains a live, weakened form of the chikungunya virus and may produce symptoms in the vaccine recipient similar to those experienced by those who contract the disease.

The safety of Ixchiq was assessed through two clinical studies conducted in North America, with approximately 3,500 participants aged 18 and older receiving the vaccine. One of these studies included around 1,000 participants who received a placebo. The most commonly reported side effects among vaccine recipients were headache, fatigue, muscle pain, joint pain, fever, nausea, and injection site tenderness.

Although not frequently reported, severe chikungunya-like reactions that prevented daily activities and required medical intervention occurred in 1.6% of Ixchiq recipients but were not seen in the placebo group. In addition, some vaccine recipients experienced prolonged chikungunya-like reactions lasting at least 30 days. The Prescribing Information for Ixchiq includes a warning about the potential for severe or extended chikungunya-like reactions following vaccination.

It is known that the chikungunya virus can be transmitted from pregnant individuals with viremia (virus present in the blood) to newborns during delivery. In one study evaluating whether the vaccine virus was present in the blood after vaccination, most individuals had vaccine virus detected in their blood within the first week following vaccination, but it was not detected 14 days after vaccination. The Prescribing Information also includes a warning that the vaccine's potential transmission from pregnant individuals to newborns and any adverse effects in the newborn are not known. Healthcare providers should consider the individual's risk of chikungunya virus exposure, gestational age, and the risks to the fetus or neonate from disease caused by the virus when deciding whether to administer the vaccine to pregnant individuals.

Ixchiq's effectiveness is based on immune response data from a U.S. clinical study involving individuals aged 18 and older. In this study, the immune response of 266 participants who received the vaccine was compared to the immune response of 96 participants who received a placebo. The antibody level evaluated in study participants was based on the level proven to be protective in non-human primates who received blood from vaccinated individuals. Almost all vaccine study participants achieved this protective antibody level.

Ixchiq was approved under the Accelerated Approval pathway, which allows the FDA to approve products for serious or life-threatening conditions based on evidence of effectiveness likely to predict clinical benefit. As a condition for approval, the FDA requires confirmatory clinical studies to verify the vaccine's clinical benefits.

Ixchiq received Fast Track and Breakthrough Therapy designations and was granted Priority Review for its application. The manufacturer of Ixchiq was also awarded a tropical disease priority review voucher by the FDA under a provision in the Food and Drug Administration Amendments Act of 2007. This provision is aimed at promoting the development of new drugs and biological products for the prevention and treatment of specific tropical diseases.

Vaccine Innovation Forum (VIF ) World 2024 will be held on Mar. 21-22, Shanghai China, which is the premier gathering for global vaccine scientists and leaders to discuss cutting-edge vaccine technologies, vaccine development progresses and partnership opportunities.