The invention provides novel adjuvants and pharmaceutical composition comprising of an adjuvant alone. The invention also provides novel vaccine compositions comprising of an antigen and a novel adjuvant. The novel adjuvant as per present invention is farnesoid-X-receptor (FXR) antagonist. The invention also relates to an adjuvant for variety of antigens. The adjuvant improves antibody production specific to incorporated antigen. The adjuvant also induces cell mediated immune response.