Zylexis® a New Approach for the Prophylaxis and Treatment of Different Diseases in Horses

It is well known that the innate immune response plays a major role in the defence of diseases. Products targeting the innate immune system are called immunomodulators. Zylexis® (Pfizer Animal Health) is an immunomodulator for the use in cats, dogs, pigs, cattle and horses. It contains inactivated parapoxvirus ovis strain D1701 as the active substance. So far, Zylexis® is licensed in Germany and several other European countries as an aid in the prevention and treatment of infectious and/or stress-induced diseases by stimulation of the proliferation of lymphocytes in dogs, cats, horses, cattle and pigs as well as the induction of antiviral interferons and interleukins (e.g. IL-6, IL-12, TNF-a) in lymphocytes of dogs, horses, cattle and pigs. The stimulation of the innate immune system starts relatively quickly, within several hours up to 2 days. The duration of action is approximately 10 to 14 days after the last injection. The product is especially useful against multifactorial infectious diseases and/or when infection pressure has increased. This broad application is only achievable due to its unique pathogen-unspecific modulation of the innate immunity.
The presentation will focus only on data generated in horses. In the first part the mode of action of Zylexis® will be shown followed by some recent equine in vitro data. The safety and efficacy data in horses will be presented in the second part. The use of Zylexis® is safe in one-day-old foals up to adults as well as in pregnant and lactating mares. The main indication for Zylexis® is the prophylaxis and treatment of upper respiratory tract infections, in particular caused by equine herpesvirus (EHV) type 1 and 4. It was demonstrated that Zylexis® treated horses showed a reduction of clinical symptoms in the model of respiratory EHV infection.
The in vivo and in vitro data clearly demonstrate that the use of Zylexis® is a safe and efficacious approach for the prophylaxis and treatment of stress-induced and infectious diseases in horses. [...]