On November 9, the U.S. Food and Drug Administration (FDA) approved the first-ever vaccine against the chikungunya virus, a mosquito-borne disease that can be fatal for certain populations.
Developed by Valneva, a member of the Biotechnology Innovation Organization (BIO), the vaccine addresses critical unmet need as the global health threat is increasingly spreading to new locations due to changing climate conditions.
What is chikungunya virus?
Chikungunya virus mainly transmits through mosquito bites, most commonly Aedes aegypti and Aedes albopictus mosquitos.
Chikungunya disease is characterized by abrupt fever, accompanied by joint pain. The joint pain is often severe and debilitating, and its effects most commonly last a few days, but in some cases, the pain may be prolonged and last weeks, or even months, according to the Centers for Disease Control and Prevention (CDC).
The disease often goes unrecognized, or misdiagnosed as the symptoms are similar to those of dengue and Zika virus.
“Infection with chikungunya virus can lead to severe disease and prolonged health problems, particularly for older adults and individuals with underlying medical conditions,” said Peter Marks, M.D., Ph.D., Director of the FDA’s Center for Biologics Evaluation and Research.
In addition to causing severe discomfort, chikungunya can be fatal to newborns and infants.
“While most people who catch chikungunya experience symptoms for about a week, a full 40 percent will feel the effects for months and even years,” with the disease causing “lifelong disability” in some patients, reported France24.
A growing global health threat
According to the BBC, as of September, healthcare professionals have registered at least 440,000 cases of chikungunya, including 350 deaths, in 2023 alone. According to the FDA, there have been at least 5 million cases of chikungunya registered since 2008.
The mosquito-borne viral disease is most commonly found in tropical and subtropical regions in Africa, Asia, and the Americas. However, due to changing climate conditions and mosquito patterns, the disease has been emerging in new regions. The World Health Organization (WHO) reported in April that chikungunya and dengue, also spread by mosquitoes, have been surging in the Americas and Europe, where the viruses have rarely been detected.
“The mosquitos and these diseases have with climate change been increasing … by altitude and by latitude,” said Diana Rojas Alvarez, WHO’s technical lead on chikungunya and dengue.
“This high transmission (in the Americas) could be an anticipation of what the next summer season in the northern hemisphere might look like,” she warned in April.
Prevention is the best protection
Currently, there are no treatments for individuals who have already contracted the virus. However, those who are at a high risk of chikungunya virus exposure and infection can be vaccinated to prevent transmission.
The vaccine, Ixchiq, is intended for the prevention of the virus and is approved for use for persons aged 18 and older.
“It contains a live, weakened version of the chikungunya virus and may cause symptoms in the vaccine recipient similar to those experienced by people who have chikungunya disease,” the FDA explains.
Two clinical studies done in North America assessed the safety of Ixchiq. Approximately 3,500 people aged 18 and above received a dose of the vaccine, while approximately 1,000 participants in one study received a placebo.
Ixchiq was approved via the FDA’s Accelerated Approval pathway, which allows the FDA to speed approval of drugs for patients with serious and life-threatening conditions based on evidence of a product’s effectiveness that is reasonably likely to predict clinical benefit.
