Vaccine set for wider use against mosquito-borne chikungunya

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An FDA-approved chikungunya vaccine manufactured by the Frederick National Laboratory and tested in early clinical trials a decade ago may become a bigger player in global health following a series of adverse event reports linked to the only other available vaccine for the mosquito-borne disease. The vaccine, Vimkunya, received FDA approval in 2025.

The name chikungunya comes from the language of the Makonde people of southeast Tanzania and northern Mozambique. It means “that which bends” for the stooped posture of patients suffering joint pain from the infection. The virus also causes high fever, fatigue, and other symptoms that can become chronic. Severe and occasionally fatal cases can occur in infants, the elderly, and people with pre-existing conditions.

In 2014, an investigational vaccine designed by the National Institute of Allergy and Infectious Diseases and manufactured by Frederick National Laboratory’s Vaccine Clinical Materials Program performed well in a phase I clinical trial, prompting a phase II collaboration between the National Institute of Allergy and Infectious Diseases and the Frederick laboratory’s Vaccine Clinical Materials Program and Clinical Monitoring Research Program directorates.

The first and only other FDA-approved chikungunya vaccine, Ixchiq, has been more widely available, having been approved two years earlier than Vimkunya. But on August 22, 2025, the FDA suspended Ixchiq’s license, citing 21 hospitalizations and three deaths linked to its use.

The FDA action has focused new attention on Vimkunya for potential use against chikungunya in endemic regions and during outbreaks of infection.

“A vaccine first tested in small early-phase studies now steps in to the world ready to blunt chikungunya’s reach,” said David Lindsay, director of the Vaccine Clinical Materials Program. “This accomplishment was shaped by years of scientific inquiry, patient trust, and commitment to public health.”

The vaccine’s phase I trial was conducted at the National Institutes of Health Clinical Center in Bethesda with 25 participants. For phase II, the Frederick laboratory’s Clinical Monitoring Research Program stepped in to help manage the international study with 400 participants in the Americas and Caribbean region, including Haiti, the Dominican Republic, Guadeloupe, Martinique, and Puerto Rico.

The team provided program and subcontractor management, and staff traveled to conduct site feasibility assessments and study initiation visits. Theresa Engel, operations director for the Clinical Monitoring Research Program said the team procured study supplies and managed logistics for shipping supplies internationally.

Last year, the World Health Organization reported a resurgence of chikungunya virus disease, with some countries experiencing substantial increases while others saw a decline. WHO counted more than 445,000 suspected and confirmed cases of chikungunya and 155 deaths in 40 countries around the world. Since 2014, chikungunya has also been reported in the Americas, with local transmission in Florida, Texas, Puerto Rico, and the U.S. Virgin Islands.