US FDA approves Valneva’s chikungunya vaccine

The US Food and Drug Administration (FDA) has granted approval to Valneva’s single-shot vaccine, Ixchiq, for the prevention of chikungunya virus in adults aged 18 and older. This marks a major milestone as the first preventive shot approved in the United States for adults suffering from chikungunya, a mosquito-borne disease.

This approval of Valneva’s chikungunya vaccine, Ixchiq, by the FDA is a significant breakthrough in the prevention of chikungunya virus, providing hope in the fight against this debilitating disease.

Chikungunya virus poses a significant global health threat, and the approval of Ixchiq addresses a critical medical need for a disease with limited treatment options. The safety and effectiveness of Ixchiq have been thoroughly evaluated, and healthcare providers are advised to consider the potential risks and benefits when administering the vaccine to pregnant individuals.

Chikungunya virus is primarily transmitted to humans through the bite of infected mosquitoes. With at least 5 million cases reported in the past 15 years, it is an emerging threat particularly prevalent in tropical and subtropical regions of Africa, Southeast Asia, and parts of the Americas.

Symptoms of chikungunya infection include fever, joint pain, headache, muscle pain, joint swelling, and rash. In some cases, individuals may experience debilitating joint pain that can persist for extended periods of time.

Ixchiq is administered as a single dose through injection into the muscle. It contains a live, weakened version of the chikungunya virus and may induce symptoms similar to those experienced by people who have had the disease. Clinical studies conducted in North America involving over 3,500 participants aged 18 and older have demonstrated the safety and effectiveness of Ixchiq.

The most commonly reported side effects among vaccine recipients were headache, fatigue, muscle pain, joint pain, fever, nausea, and tenderness at the injection site. Severe chikungunya-like adverse reactions were infrequent, occurring in 1.6 percent of Ixchiq recipients, and required medical intervention. Notably, no severe adverse reactions were reported in the placebo group. While two recipients with severe reactions were hospitalized, some individuals experienced prolonged chikungunya-like adverse reactions lasting at least 30 days.

To further assess the risk of severe chikungunya-like adverse reactions, the FDA has mandated Valneva to conduct a postmarketing study. Additionally, it has been reported that pregnant individuals with viremia (virus present in the blood) at delivery can transmit the chikungunya virus to newborn babies, potentially leading to severe and fatal chikungunya virus disease. The vaccine’s prescribing information includes a warning regarding the transmission of the vaccine virus and its potential effects on newborns. Healthcare providers are advised to carefully consider the risks and benefits for pregnant individuals before administering the vaccine.

The effectiveness of Ixchiq is based on immune response data from a clinical study conducted in the United States. Nearly all vaccine study participants achieved the antibody level necessary for protection, as demonstrated in non-human primates that received blood from vaccinated individuals. The FDA granted accelerated approval to Ixchiq, a pathway that allows for the approval of products for serious or life-threatening conditions based on evidence of effectiveness likely to predict clinical benefit. Confirmatory clinical studies will be conducted to validate the clinical benefits of Ixchiq.