Researchers in Spain and Peru are working towards developing a vaccine against Chagas disease caused due to the bite of an assassin bug. It is found to infect an estimated 12 million people in Latin America, killing tens of thousands each year.
To date, no vaccine exists against 'protozoans', a group of microscopic parasites that includes Trypanosoma cruzi the causative agent of Chagas disease renowned for their capacity to evade the human immune system. Trypanosoma cruzi usually enters humans, when they are bitten by insects called assassin bugs. The disease is also transmitted through blood transfusions, and from mother to child during pregnancy.
For developing the vaccine researchers used one of the parasite's genes as the basis for a 'DNA vaccine'. When injected into mammals, the vaccine, which contains fragments of DNA, causes the recipients' cells to produce a protein that would ordinarily be produced only by the parasite. This in turn triggers an immune response to the protein, even though the parasite is not present. Thus if the individual is later infected by the parasite, the host's immune system will be able to recognize it and act against it. Researchers say they noticed a high degree of protection when the vaccine was used to treat laboratory animals. The protein that researchers used in the potential vaccine controlled the parasite's ability to take up molecules of fat through its surface.
Thus researchers conclude on a positive note saying that they are one day hoping to take the vaccine up to the stage of clinical trials.