New Synthetic Vaccine Targets Chikungunya Virus

While the benefits of vaccines are indisputable, the fact that almost all vaccines require refrigeration can be an obstacle to their distribution and use in underdeveloped nations. Partly because of these infrastructure problems, poorer countries tend to suffer disproportionately during disease outbreaks.

Now, a new synthetic vaccine that contains no actual genetic material, and thus is stable in warm environments, could be a game changer in underserved areas experiencing outbreaks of Chikungunya. The Chikungunya virus, spread by mosquitoes, can be debilitating although it rarely results in death. There currently is no vaccine available for the illness.

Investigators at the French National Centre for Scientific Research in Grenoble, France and the University of Bristol in England, along with cloud computing specialists at Oracle, worked to engineer a thermostable vaccine that can be produced quickly, accurately, and relatively inexpensively using cloud infrastructure to process vast sets of data.

The new synthetic Chikungunya vaccine has its roots in a protein known as ADDomer, which naturally assembles itself into a buckyball-shaped particle comprised of multiple groups of spherical balls. This particle resembles a real virus, and it can be manipulated to act as such.

“The cool thing is that you can very easily engineer the surface of this particle,” Imre Berger, PhD, HDR, FRSB, the founding director of the Max Planck Centre for Minimal Biology at the University of Bristol and a co-author of the study, told Contagion®. “You can, for example, graft harmless bits and pieces from a real virus—like Chikungunya—on the surface of the ADDomer. When you inject this ADDomer with the Chikungunya bits on its surface into an animal, or one day into humans, then the body is tricked into thinking it is challenged by the real Chikungunya virus. This stimulates the immune system to make antibodies to defend itself. These antibodies will then also defend against the real Chikungunya virus.”

The synthetic vaccine was tested on mice and found to be quite effective. Mice who were injected with the engineered vaccine responded with high levels of antibodies against Chikungunya. The control mice in the study did not have this reaction.

The synthetic Chikungunya vaccine came about as the result of an accidental discovery by Pascal Fender, PhD, of the French National Centre for Scientific Research, who “simply forgot a test tube with ADDomer inside in his lab coat,” Berger said. “This was in Grenoble, in southern France. It becomes quite hot there in the summer, and the labs have no air conditioning.” When Fender used a microscope to examine the contents of the test tube after it had been sitting in his pocket, he found that the buckyball-shaped particle was intact despite the heat. Fender and his colleagues realized they had the potential to use this finding to create a thermostable vaccine.

The investigators chose to focus on a vaccine for the Chikungunya virus because of headline-making disease outbreaks in France a few years ago, when this research began. They don’t plan to limit their efforts to Chikungunya, however. “ADDomer is a platform which can be leveraged against many infectious diseases caused by viruses,” Berger said. “[W]e now have made...more than 30 vaccine candidates against a range of human (Zika, dengue, influenza) and veterinary (Gumboro [and] Newcastle) diseases.”

In addition to their ability to remain stable and effective at various temperatures, ADDomer-based vaccines are cost effective and simple to create. “ADDomer is also very soluble, so vaccine doses can come in smaller volumes, which causes less pain and adverse reaction,” Berger noted.

The scientists involved in the creation of the synthetic Chikungunya vaccine have formed a start-up company called Imophoron, based in Bristol, that will concentrate on continuing ADDomer research in non-human and primates as well as navigating the regulatory process by which vaccines are made available for distribution.