This report describes a case of accidental needlestick injury involving a live equine vaccination, Equilis StrepE. A vet presented herself to the Emergency Department having accidentally injected herself with an equine vaccination. Her left thumb (injury site) was inflamed and had lymphangitis progressing proximally along her left arm. Her inflammatory markers were not raised. The swelling, erythma and lymphangitis had improved markedly with intravenous antibiotics. She had no sequelae at follow-up. Equilis StrepE is a vaccine for submucosal administration containing a modified live avirulent strain of Streptococcus equi subspecies equi (Strain TW). Group C streptococci infections are pathogenic in horses and uncommon in humans. A search of the literature revealed no prior case report of similar adverse reaction to this vaccine. The vaccine may have harmful effect on human health, if injected accidentally but more evidence needs to be collected.