Scientists have taken a step closer to an effective vaccine against Strangles, a scourge of the equine world that causes considerable pain and suffering to horses and ponies worldwide.

An international team from the UK’s Animal Health Trust, Sweden’s Karolinska Institute, the Swedish University of Agricultural Sciences and Intervacc AB have been working together since 2003 to develop a vaccine that is protective, safe and enables differentiation of infected from vaccinated animals (DIVA). First author, Dr Carl Robinson from the Animal Health Trust commented “For a long time there has been an unmet need. We have used the knowledge gained from genome sequencing and in vitro studies to inform the choices made in the design of the vaccine. The latest formulation of Strangvac, a protein based-vaccine, is ticking all the boxes”.

Their work has been published in the journal Vaccine.

Strangles is caused by the host-restricted bacterium Streptococcus equi. Affected animals develop abscesses around the head and neck, putting pressure on internal structures and exuding highly infectious pus that represents a threat to uninfected horses. In some cases, life-threatening complications of the disease may occur, including bleeding from mucous membranes and abscessation at other locations around the body.

Dr Robinson said, “With over 600 outbreaks a year in the UK alone, strangles represents a significant welfare issue as well as thrusting a massive financial burden on owners and equine businesses, these promising results couldn’t have come at a better time.”

“We are delighted to have shown that our Strangvac® vaccine protected over 80 % of horses from this dreadful disease. Additional clinical trials using intra muscular vaccination have confirmed the efficacy and the excellent safety profile,” said Prof. Jan-Ingmar Flock, CEO of Intervacc AB, the company behind the vaccine.

“Strangvac® has the potential to prevent many thousands of horses from falling ill each year. Transfer of the manufacturing process and production of commercial batches are underway towards the registration and launch of Strangvac,” continued Prof. Flock “and we anticipate that Strangvac® will be available for use during 2020.”

Reference
Strangvac: A recombinant fusion protein vaccine that protects against strangles, caused by Streptococcus equi. Carl Robinson, Lars Frykberg, Margareta Flock, Bengt Guss, Andrew S. Waller, Jan-Ingmar Flock. Vaccine, available online 2 February 2018 ahead of print, https://doi.org/10.1016/j.vaccine.2018.01.030.