The invention relates to compositions, uses, and methods for inducing an immune response against a vaccinia virus. The addition of an oil and water emulsion to MVA can vastly increase the B cell response and particularly neutralizing antibodies against vaccinia virus and encoded recombinant antigens. Thus, the addition of an oil and water emulsion to MVA can increase the protective immune response. The invention encompasses administering a dose of an MVA in an oil and water emulsion to an animal, especially a human.