Researchers make breakthrough in finding a vaccine against horse disease strangle

A research group at the Department of Microbiology, Swedish University of Agricultural Sciences (SLU) in Uppsala, Sweden has - in collaboration with J-I Flock's research group at the Karolinska Institutet medical university in Stockholm, the pharmacological company Intervacc AB, Stockholm and the Animal Health Trust in the UK - after many years of research made a breakthrough in finding a vaccine against the horse disease strangle.

Strangle is a most contagious disease caused by the bacteria Streptococcus equi. The disease results in high fever and characteristically swollen lymphoid glands in the neck region generating large boils that often burst. Most contaminated horses recover and become immune against the disease, but in worst cases strangle can be fatal. A stable where strangle has been discovered must be put in quarantine causing economical losses and practical problems. The disease is spread worldwide; in Sweden some 100 cases are reported annually, in the UK circa 1,000 cases per year are reported.

Today there exists no safe and efficient vaccine against strangle, and previous vaccines are based on live bacteria, which is hazardous and may cause severe side effects. The new vaccine is based on pure proteins produced by recombinant DNA technology. The vaccine consists of seven different Streptococcus proteins, and the results from injecting horses have been most positive so far, i.e. the vaccine is highly protective and has shown no side effects.

The goal is to have the new strangle vaccine commercially available in a near future. The research results also imply a possibility to develop protein-based vaccines against other Streptococcus infections in animals as well as humans, e.g. tonsillitis.

"This is a most exciting project, where basic research results in new applications and new knowledge can be used to develop vaccines against other bacteria. This in turn is highly important considering the increased number of infectious diseases caused by antibiotica-resistent bacteria", comments research leader, Professor Bengt Guss at SLU.