Bovine immune response to leptospira antigen in different novel adjuvants and vaccine delivery platforms.

•Leptospira vaccines for cattle can be improved by the use of novel adjuvants.•Efficacious cattle vaccines induce humoral and cellular immunity, including IL-17A.•Two different polymer formulations enhanced responses to leptospira antigen in cattle.•Oil-based adjuvant enhanced magnitude of Th1 type immunity to leptospira antigen.