Saint-Herblain (France), April 18, 2025 Valneva SE (Nasdaq: VALN; Euronext Paris: VLA), a company focused on vaccine development, made a significant announcement today regarding its single-dose vaccine, IXCHIQ, designed for the prevention of chikungunya virus (CHIKV) infections. This update comes following the recent meeting held on April 16, 2025, where the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC) revised its recommendations for the use of this vaccine.

The ACIP has maintained its existing recommendation for IXCHIQ for individuals aged 18 and older who are traveling to regions experiencing an outbreak of chikungunya. Furthermore, the committee indicated that the vaccine may also be advised for adults aged 18 and older who are planning to travel or settle in areas that currently do not have an outbreak but pose a significant risk to U.S. travelersespecially for those who intend to stay for an extended period, such as six months or more.

Additionally, the ACIP has issued a precautionary recommendation regarding the use of IXCHIQ for individuals aged 65 and older. This measure comes in light of an ongoing investigation by the CDC into six reported cases of serious adverse events (SAEs), including five hospitalizations, occurring in individuals aged between 67 and 86 years after receiving the IXCHIQ vaccine. These adverse events were reported through the Vaccine Adverse Event Reporting System (VAERS), a system designed to serve as an early warning tool for potential safety issues related to vaccines, although it typically does not establish causation.

It is noteworthy that all hospitalized patients in these cases had preexisting comorbidities. The ACIP concluded that while a causal link to IXCHIQ is plausible, none was definitively established, warranting further investigation.

Despite these concerns, the ACIP noted that vaccination with IXCHIQ could be indicated in high-risk situations for individuals aged 65 and older, especially during outbreaks, considering the known risks of severe illness and hospitalization in this age group. For example, earlier this month, Valneva delivered 40,000 doses of IXCHIQ to the French island of La Runion, where the regional health agency (ARS) prioritized vaccination for adults 65 and older, particularly those with comorbid conditions, in an effort to safeguard the population during an ongoing chikungunya outbreak. Valneva has also recently received confirmation from the ARS for an additional order of 50,000 doses of IXCHIQ as part of ongoing efforts to control this epidemic.

To date, Valneva has provided approximately 80,000 doses of IXCHIQ across the United States, Canada, and Europe. It is important to note that no additional serious adverse events have been reported globally since January 2025, and Valneva has not identified any safety signals inconsistent with the product's indication in the United States as part of its ongoing post-marketing surveillance, which includes periodic safety reports and systematic signal detection activities communicated to the U.S. Food and Drug Administration (FDA).

Dr. Juan Carlos Jaramillo, the Chief Medical Officer of Valneva, stated, "Valneva remains committed to adhering to the highest safety standards, and the safety profile of IXCHIQ remains unchanged and positive. We respect the ACIP's recommendation and acknowledge the importance of continuing the rigorous monitoring protocols in place. We encourage healthcare providers to assess the benefits and risks of vaccination based on each individual's medical history and travel plans, in accordance with the current guidance.".

The ACIP's recommendations are pending final approval from the CDC Director and the U.S. Department of Health and Human Services.

Understanding Chikungunya

Chikungunya virus (CHIKV) is a viral disease transmitted to humans through the bites of infected Aedes mosquitoes. The illness is characterized by symptoms such as fever, severe joint and muscle pain, headaches, nausea, fatigue, and skin rashes. The joint pain associated with chikungunya can be debilitating and may persist for weeks or even years.

Since its rapid spread beginning in 2004, chikungunya has caused widespread outbreaks worldwide, with the virus now identified in over 110 countries across Asia, Africa, Europe, and the Americas. From 2013 to 2023, over 3.7 million cases were reported in the Americas, and the economic impact of the disease is considered to be significantly burdensome. Moreover, the medical and economic ramifications of chikungunya are expected to continue escalating as the mosquito vectors expand their range. In this context, the World Health Organization (WHO) has emphasized that chikungunya represents a major public health threat.

About Valneva SE

Valneva is a biotechnology company that focuses on the development, production, and commercialization of prophylactic vaccines aimed at addressing unmet medical needs in infectious diseases. Valneva employs a highly specialized approach and leverages its expertise in various vaccination methods to create vaccines for diseases that currently lack effective vaccines or for which existing solutions can be improved.

The company has a robust research and development pipeline that has successfully advanced several vaccines from early-stage research to market. Valneva currently markets three travel vaccines, including the worlds first vaccine against chikungunya, in addition to various vaccines from third parties.

The growing commercial activities of the company contribute to the ongoing advancement of its vaccine portfolio, which includes the only advanced clinical stage Lyme disease vaccine candidate in collaboration with Pfizer, the most advanced candidate vaccine against Shigellosis, as well as candidates for the Zika virus and other public health threats. More information can be found on the company's website at laetitia.bachelot-fontaine@valneva.com

Joshua Drumm, Ph.D.
VP Global Investor Relations
M +001 917 815 4520
joshua.drumm@valneva.com

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