Occurring across Asia, Africa, and the Indian subcontinent, Chikungunya is a little known tropical disease that is thought to infect at least 3 million people every year. Spread by mosquitoes, it has recently had epidemics in both Europe and the Americas, yet currently, with no cure, all doctors can do is treat the symptoms. Researchers have now, however, created what could be a vaccine to protect against the virus.
Chikungunya is classified by the World Health Organization, alongside the Dengue virus, as one of 20 or so “neglected tropical diseases”. These are a group of illnesses that predominantly infect the poorest people on the planet who live in the developing world, and despite collectively infecting an estimated 1.4 billion people, do not have the same focus or funding generally given to other more high profile diseases, namely HIV/AIDS, tuberculosis, and malaria.
The virus is transmitted via infected mosquitoes. The name “chikungunya” translates as “to become contorted”, in reference to severe joint pain and fever, as well as headaches and a rash, which usually last for a few weeks but can extend for months and even years. In really particularly severe cases, it can even lead to death. There is currently no cure for the disease, and treatment usually involves treating the symptoms instead.
But now researchers from the University of Texas may have developed the first effective vaccine, published in Nature Medicine. Rather than using live-attenuated or inactivated chikungunya viruses, which is how vaccines are usually created, the researchers have taken an insect virus and edited it to create a hybrid.
By making the Eilat virus, which normally infects mosquitos’ express Chikungunya proteins, they managed to create a hybrid that was structurally identical to the natural Chikungunya virus. The main difference being that because it is based on the Eilat virus, it cannot infect mammal cells. When the researchers tested this vaccine on mice, they found that four days after a single dose, the rodents were producing antibodies primed against the Chikungunya virus that lasted in the body for 290 days.
The team of scientists has even tested the new vaccine on non-human primates and found that it gave them a robust immunity to the disease. “This vaccine offers efficient, safe and affordable protection against chikungunya and builds the foundation for using viruses that only infect insects to develop vaccines against other insect-borne diseases,” explained lead researcher Professor Scott Weaver.