FIELD-EVALUATION OF THE EFFICACY OF ROMOVAC-50, A NEW INACTIVATED, ADJUVANTED BOVINE ROTAVIRUS VACCINE

An inactivated bovine rotavirus vaccine, prepared with an adjuvant whi ch gives a water-in-oil emulsion (Montanide ISA 50, adjuvant) was used in field trials for prevention of calf neonatal diarrhoea. The vaccin e, which was designated as Romovac 50, when injected into cows in thei r last month of pregnancy, proved to be as effective as the traditiona l vaccine prepared with Freund's incomplete adjuvant. Thus, the incide nce of the naturally occurring neonatal diarrhoea was significantly re duced in calves which were fed mammary secretion from their vaccinated dams, compared to the calves delivered from the unvaccinated cows. Ro movac 50 also has the advantages over the traditional Freund's adjuvan ted vaccine in that it is less viscous and thus more readily injected and less irritant to tissues.