Lactogenic immunity following vaccination of cattle with bovine coronavirus

Abstract

In order to investigate the ability of an oil adjuvanted vaccine containing bovine coronavirus antigen to enhance lactogenic immunity in the calf, pregnant cows and heifers were vaccinated and specific virus neutralising antibody levels determined in serum, colostrum and milk. Pre-existing antibody titres (as a result of natural infection) in the serum of these animals were found to be significantly increased as a result of a single shot vaccination carried out between 2 and 12 weeks before calving. This was reflected in a similar increase in the titre and duration of specific antibody in milk and colostrum that was passed on to the calves. The overall response observed was highly dependent on an adequate antigen payload being incorporated within the single dose vaccine. No abnormal local or systemic reactions were observed as a result of vaccination. It is hoped that this approach will lead to the production of a superior commercial vaccine for the protection of neonatal calves against enteric coronavirus infection.

Fig. 1

BCoV antibody response following immunisation with combined E. coli, rotavirus and coronavirus vaccines containing different concentrations of BCoV antigen (⋅ 190 units per dose, ■ 38 units per dose, ♦ 7.6 units per dose, × unvaccinated controls). Graphs show the specific serum antibody responses as measured by HAI (a) and VN (b). Error bars denote 95% confidence limits.

Fig. 2

Mean BCoV VN antibody results in sera and milk from vaccinated (■) and placebo treated (□) cows and sera from their respective calves. Studies were carried out on four farms, two beef suckler herds (a and b) and two dairy herds (c and d) and samples were obtained at vaccination (V), calving (C) or at the number of days indicated after the event. Error bars denote 95% confidence limits.