Chikungunya: Experimental vaccine successfully tested in monkeys

November 20, 2015

To create the virus-like particles used in the experimental vaccine, the researchers used genetic engineering techniques to produce the structural proteins that produce the spiky, roughly spherical exterior possessed by chikungunya viruses before they have entered a cell. The proteins then assembled themselves into harmless balls that resembled particles of Sindbis virus - a relative of chikungunya and a fellow member of the alphavirus genus, which also includes a number of insect-borne viruses capable of causing dangerous encephalitis in humans.

Serum drawn from rhesus macaques injected with the virus-like particles contained substantial levels of antibodies that inactivated chikungunya virus. Two groups of macaques were then inoculated, either with virus-like particles or with a sham solution containing no vaccine. When the researchers challenged the monkeys by injection with chikungunya 15 weeks later, they found that the vaccine had completely protected the animals from the virus.

Dr.Gary Nabel, director of the NIAID's Vaccine Research Center and corresponding author on the Nature Medicine paper, said that the vaccine's effectiveness against chikungunya had led his group to plan follow-up investigations into whether the same approach would work against other alphaviruses, such as Western and Eastern equine encephalitis viruses (both responsible for periodic outbreaks in the United States), and Africa's o'nyong-nyong virus.

Source: University of Texas Medical Branch at Galveston