Preliminary research from Cornell University indicates that the commercial vaccine containing weakened live viruses (Rhinomune), called a modified live vaccine (MLV), appears to be more effective in preventing equine herpesvirus (EHV) than killed vaccines and offers protection against the neurologic form of EHV. Klaus Osterrieder, DVM, DVM Habilitation (a German equivalent to a PhD), associate professor of virology in the College of Veterinary Medicine at Cornell, announced his findings prior to peer-reviewed journal publication because of the recent deadly outbreaks of EHV.

“It’s important that people know that the MLV has been in use for decades, has proven to be reasonably safe, and–in my opinion–it should be the vaccine of choice, at least in non-pregnant animals,” said Osterrieder.

Osterrieder’s preliminary study compared the effectiveness of the MLV vaccine to a killed vaccine for equine herpesvirus. Osterrieder vaccinated five horses with the MLV and five with an inactivated virus; five received no vaccination (control group). None of the 15 horses was pregnant. The horses were then exposed to the 2003 Findley, Ohio, EHV outbreak’s neurologic herpesvirus.

The study found that the horses with the MLV vaccination consistently had lower fevers, no neurological disorders, and less virus in nasal fluids. One horse vaccinated with the inactivated virus and one from the control group showed mild neurologic symptoms. All of the horses fully recovered