Chagas Disease Vaccine Promise

Kissing bugs
Chagas disease (or American trypanosomiasis) causes fever, fatigue, body aches, headache, rash, loss of appetite, diarrhoea, and vomiting. As well as growing in cases in the U.S. (particularly in Texas), it is a major cause of heart disease and gastrointestinal dysfunction in widespread areas throughout Latin America.
Chagas disease is caused by the tiny worm-like parasite Trypanosoma cruzi, which is carried by so-termed Kissing Bugs (the insects tend to leave bites around the mouth, specially while people are sleeping at night). Additionally, there is some evidence that bed bugs can also carry the parasite.
Currently there is no vaccine available. Treatment tends to be with anti-parasitic drugs (for those fortunate enough to be able to afford them).

In a new study, researchers report on success in developing the vaccine in mice infected with the disease causing parasite. Research has been led by scientists based at the University of Texas Medical Branch in Galveston, USA.

Trypanosoma parasite

Trypanosoma parasite forms in blood smear from patient with African trypanosomiasis.

The study showed that mice that were infected with T. cruzi immediately after vaccination were able to maintain parasite numbers at a low level during a period of acute infection. No mice showed inflammation in muscle tissue. The vaccine was composed of T. cruzi proteins (called TcG2 and TcG4). These proteins had been shown to be the most potent in initiating antibody and a T-cell immune response.

Early results are promising and the conferred immunity appears to be long-lasting (up to six-months.) However, in order for a vaccine to be developed which is effective in people further research is required.

The new research has been published in the journal PLOS Pathogens. The research paper is called “A Two-Component DNA-Prime/Protein-Boost Vaccination Strategy for Eliciting Long-Term, Protective T Cell Immunity against Trypanosoma cruzi.”

About the author

Tim Sandle

Dr. Tim Sandle is a chartered biologist and holds a first class honours degree in Applied Biology; a Masters degree in education; and has a doctorate from Keele University.