Immunity in cattle vaccinated against ringworm.

Protective properties of a live, freeze-dried vaccine against ringworm, produced by Bioveta, Ivanovice na Hané, Czechoslovakia, were tested in a group of 422 calves. Vaccinated and control calves were challenged by epicutaneous inoculation of a virulent culture of Trichophyton verrucosum. Between 4.4 and 9.5% of calves challenged between days 14 and 25 after revaccination showed only mild clinical signs of ringworm and 99-100% were fully protected from day 28, the immunity persisting for at least one year. All control calves showed signs of ringworm after challenge. In most cases, extensive mycotic lesions, also penetrating into deep skin layers, were observed. Protective properties of the Czechoslovak vaccine and a USSR vaccine were high and comparable.