Vitamin E as an Adjuvant in an Escherichia coli J5 Vaccine

Abstract

Vitamin E was tested as an adjuvant in an Escherichia coli (0111:B4) J5 vaccine. Twenty cows were assigned to five groups of 4 cows. Cows in four groups were vaccinated with an E. coli J5 bacterin containing 5ml of 109 boiled cells/ml. Vaccinations were at drying off, 30 d after drying off, and within 48h after calving. Vaccine adjuvants differed among groups. The four treatment adjuvants were 5ml of Freund's incomplete adjuvant, 5ml of vitamin E, 2.5ml of Freund's plus 2.5ml of vitamin E, and 5ml of PBS. Cows in the fifth group were unimmunized controls. A front mammary quarter of each cow was challenged by infusion of 10µg of E. coli J5 lipopolysaccharide approximately 4 wk into lactation. Vitamin E alone enhanced serum IgM titers but had no effect on milk IgM or serum and milk IgG titers. The mixture of Freund's plus vitamin E resulted in peak IgG titers in serum and milk comparable with that of Freund's alone. Persistency of IgG titers in cows immunized with the Freund's plus vitamin E mixture was greater than the persistency of titers for cows immunized with the vaccine containing Freund's alone as the adjuvant. The mixture of Freund's plus vitamin E had a synergistic effect in reducing severity of systemic clinical signs.