US Suspends Ixchiq Chikungunya Vaccine Over Serious Side Effects

US health authorities have suspended the license for the Ixchiq vaccine against the chikungunya virus due to reports of “serious adverse events.” The decision, announced by the French manufacturer Valneva on August 25, 2023, follows an order from the US Food and Drug Administration (FDA) issued on Friday. Ixchiq was one of only two vaccines approved by the FDA for the mosquito-borne virus, which has been increasingly identified in non-endemic regions worldwide.

Valneva obtained US approval for Ixchiq in 2023, but concerns regarding side effects, particularly in older patients, have prompted further scrutiny. The company reported four additional serious side effects, three of which occurred in individuals aged between 70 and 82. This has led the European Medicines Agency (EMA) to also review the vaccine’s safety profile this year.

Public Health Concerns and Global Threats

The suspension of Ixchiq comes at a time when public health experts are raising alarms about the potential for chikungunya to become a global health crisis. Climate change is facilitating the spread of mosquitoes that carry the virus into new regions, increasing the likelihood of outbreaks. Symptoms of chikungunya resemble those of dengue fever and Zika virus, featuring high fever and debilitating joint pain. Although the illness is rarely fatal, it poses a heightened risk to vulnerable populations, including the elderly and infants.

In a statement, Valneva’s Chief Executive Officer, Thomas Lingelbach, emphasized the company’s commitment to ensuring access to its vaccine as a critical public health tool, stating, “As we determine potential next steps, and as the clear threat of chikungunya continues to escalate globally, Valneva remains fully committed to maintaining access to our vaccine.”

The World Health Organization (WHO) has previously warned of the risks associated with a significant chikungunya epidemic, urging for immediate action. The organization noted that current indicators resemble those seen before a major outbreak two decades ago, which affected nearly half a million individuals worldwide.

Recent Trends in Europe

Recent data from the European Centre for Disease Prevention and Control (ECDC) indicates that Europe has experienced 27 chikungunya outbreaks this year, setting a new record for the continent. The rapid increase in cases underlines the urgent need for effective public health responses to prevent further transmission.

As the suspension of Ixchiq unfolds, the implications for vaccination programs and public health strategies will be closely monitored, both in the United States and globally. The ongoing situation underscores the importance of vigilance as health authorities respond to the evolving landscape of infectious diseases.