Valneva Launches Chikungunya Vaccine Pilot Program in Brazil | Ixchiq
- São Paulo, Brazil – A pilot vaccination program utilizing Valneva’s single-shot chikungunya vaccine, IXCHIQ®, has commenced in Brazil, marking a significant step in the fight against the mosquito-borne...
- The pilot program is designed to evaluate the effectiveness and safety of IXCHIQ® in a real-world setting, generating crucial data from a large population.
- The vaccination effort will focus on ten strategically selected municipalities across Brazil, targeting adults aged 18 to 59.
São Paulo, Brazil – A pilot vaccination program utilizing Valneva’s single-shot chikungunya vaccine, IXCHIQ®, has commenced in Brazil, marking a significant step in the fight against the mosquito-borne virus. The initiative, a collaboration between Valneva SE and the Instituto Butantan, one of the world’s largest biomedical research centers, began on .
The pilot program is designed to evaluate the effectiveness and safety of IXCHIQ® in a real-world setting, generating crucial data from a large population. According to a joint statement, the program will serve as the basis for post-marketing commitment studies. Up to 500,000 doses of the vaccine are being donated through the Instituto Butantan to the Brazilian Ministry of Health for this purpose.
The vaccination effort will focus on ten strategically selected municipalities across Brazil, targeting adults aged 18 to 59. Authorities aim to achieve a vaccine coverage rate of 20% to 40% within these communities, addressing public health needs as outlined by the Brazilian Ministry of Health to mitigate chikungunya transmission.
Brazil has been disproportionately affected by chikungunya, reporting over one million cases between January 2019 and July 2024. In 2024 alone, the country recorded 263,502 cases, resulting in 246 deaths, according to data released by Valneva. This makes Brazil the nation hardest hit by the virus in the Americas.
IXCHIQ® received market authorization in Brazil in April 2025 for use in individuals 18 years of age, and older. The vaccine is a live attenuated single-dose formulation, meaning it contains a weakened version of the chikungunya virus designed to stimulate an immune response without causing severe illness.
The collaboration between Valneva and Instituto Butantan extends beyond this pilot program. In 2021, the two entities signed a technology transfer agreement, ensuring the development and commercialization of the vaccine in Latin America. This agreement underscores a commitment to regional self-sufficiency in vaccine production and accessibility.
Valneva’s Chief Medical Officer emphasized the company’s commitment to global preparedness against chikungunya threats, stating that the initiative is expected to generate critical real-world data that reinforces the vaccine’s public health value. The data collected during the pilot program will be instrumental in informing future vaccination strategies and potentially expanding the use of IXCHIQ® to other endemic regions.
While the launch of the pilot program represents a positive development in the fight against chikungunya, We see important to note recent safety concerns surrounding the vaccine. On , the US Food and Drug Administration (FDA) temporarily suspended the biologics license for IXCHIQ® due to serious safety concerns related to chikungunya-like illness in vaccine recipients. The FDA reported one death from encephalitis directly attributable to the vaccine and over 20 reported serious adverse events.
However, the FDA subsequently removed the recommended pause in use on , and approved required updated labeling. This decision suggests that the benefit-risk profile of the vaccine, under most scenarios, was deemed acceptable following further evaluation. The updated labeling likely contains information regarding potential adverse events and guidance for healthcare professionals.
Chikungunya is a viral disease transmitted to humans through the bites of infected mosquitoes, primarily Aedes aegypti and Aedes albopictus. Symptoms typically include fever and joint pain, which can be debilitating and persist for weeks or months. While rarely fatal, chikungunya can cause significant morbidity and economic burden in affected communities.
The initiation of this pilot program in Brazil represents a crucial step towards understanding the real-world impact of IXCHIQ® and its potential to alleviate the burden of chikungunya in a region heavily affected by the virus. The data generated will be closely watched by public health officials and vaccine developers worldwide.