Strangvac® clinical trials confirm expected efficacy

A series of trials have been conducted at the Animal Health Trust, Newmarket, England. The trials were aimed to measure the safety, immunogenicity, efficacy and DIVA (differentiates infected from vaccinated animals) capability of the Strangvac® vaccine. The vaccinations were well tolerated throughout the studies and no adverse events were identified.


Intramuscular administration of Strangvac® consistently induced the production of antibodies against the vaccine components in all animals. The dynamics of the induced antibody response were typical of those induced by commercial vaccines.


Efficacy – Onset of immunity

Two doses of Strangvac® significantly delayed the onset and reduced the severity of disease induced by challenge two weeks post basic vaccination.


Efficacy – Duration of immunity
Strangvac® vaccination reduced the amount of clinical disease at two months post basic vaccination.


Efficacy – Onset of immunity following re-vaccination

Strangvac® conferred excellent levels of protection against challenge with S. equi two weeks post re-vaccination.


DIVA capability

Strangvac® has DIVA capability, which will be invaluable for the use of this vaccine in populations of horses where infection with S. equi is endemic.


The vaccine was safe, immunogenic and effective, particularly at two weeks post third vaccination. Furthermore, Strangvac® has DIVA capability enabling this vaccine to be used alongside conventional disease prevention strategies.

Strangvac® will play a significant role in the prevention of Strangles in horses, in particular through the re-vaccination of horses following the identification of an index case or prior to the transportation of an animal to equine events where there is a risk of exposure to S. equi.

Intervacc CEO, Jan-Ingmar Flock, comments that it is with great pleasure that we now have been able to get the results from the final studies at Animal Health Trust. These final clinical trials confirm the data we have observed in previous explorative studies and provide evidence that intramuscular vaccination with Strangvac® provides good protection against strangles.

Dr. Andrew Waller, at Animal Health Trust, who has been Principal Investigator for the clinical trials conclude that Strangvac® will play a significant role in the prevention of Strangles in horses.