The chikungunya virus, which is spread by mosquitoes, causes high fever, severe joint pain, fatigue, and other symptoms. An experimental vaccine manufactured at the Pilot Plant appears to offer protection against the virus, according to results from first-in-human clinical trials. Feature image by A2-33 (Own work) via Wikimedia Commons.
Published:
9/12/2014

An experimental vaccine for mosquito-borne chikungunya virus, which spread to the U.S. this year, appears to be safe and well-tolerated while offering protection against the virus, according to the results of a first-in-human clinical trial.

The vaccine—made from non-infectious virus-like particles (VLPs)—was manufactured at the Pilot Plant (formerly known as the Vaccine Pilot Plant), which is operated by the Frederick National Laboratory for Cancer Research for the National Institute of Allergy and Infectious Diseases (NIAID).

The chikungunya virus, which is spread by mosquitoes, causes high fever, severe joint pain, fatigue, and other symptoms. An experimental vaccine manufactured at the Pilot Plant appears to offer protection against the virus, according to results from first-in-human clinical trials.

“Eleven months after vaccination, antibody levels were comparable to those seen in people who had recovered after natural chikungunya infection, suggesting that the VLP vaccine could provide long-term protection against the virus,” corresponding author Julie Ledgerwood, D.O., of NIAID’s Vaccine Research Center, said in a news release on the research paper published in The Lancet.

Since 2004, chikungunya virus has been a growing health threat in Africa, Asia, and Europe. Last year, it spread to the Americas. As of August 12, 2014, 580 travel-associated cases have been reported in the U.S., including 13 in Maryland, according to the Centers for Disease Control and Prevention (CDC). Four mosquito-to-human cases have been reported in Florida.

The disease causes high fever, severe joint pain, fatigue, and other symptoms, which can relapse months after the initial bout and persist chronically. The name chikungunya comes from the language of the Makonde ethnic group of southeast Tanzania and northern Mozambique. It means “that which bends,” referring to the stooped posture of afflicted individuals suffering from joint pain. There is currently no vaccine or treatment.

The VLP vaccine is composed of the exterior structural proteins of the West African virus strain (37997) that can stimulate an immune reaction without risk of infection. The vaccine does not contain the virus’ genetic material.

In a Phase 1 dose-escalation clinical trial, 25 healthy individuals ages 18 to 50 were divided into three groups, each of which was injected three times—initially and again at 4 and 20 weeks—with one of the following doses: 10, 20, or 40 micrograms of vaccine. All doses were well-tolerated, without significant side effects. Neutralizing antibodies were detected in all individuals after the second vaccination, and a significant boost in antibodies occurred after the third injection.

“The vaccine also generated antibodies against multiple genotypes of the virus, suggesting that it could be effective against any strains of the virus,” Ledgerwood said.

In a commentary linked to The Lancet paper, Ann Powers, Ph.D., of the CDC, expressed concern about the commercialization of a vaccine for a mosquito-borne disease because the demand might not be large enough to justify a drug company’s multimillion-dollar investment to bring such a product to market.

“Yet, even with this need for substantial funding, vaccines are still the most cost-effective strategy for disease prevention,” she wrote. “In view of the burden of chikungunya outbreaks, which have affected up to 63 percent of local populations in a matter of months, the continued development of this VLP vaccine candidate, along with other vaccine options, should be encouraged.”

Image: The chikungunya virus, which is spread by mosquitoes, causes high fever, severe joint pain, fatigue, and other symptoms. An experimental vaccine manufactured at the Pilot Plant appears to offer protection against the virus, according to results from first-in-human clinical trials. Feature image by A2-33 (Own work) via Wikimedia Commons.

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