 Monoclonal antibodies can be acquired in the immune system via passive immunity or active immunity.The advantage of active monoclonal antibody therapy is the fact that the immune system will produce antibodies long-term, with only a short-term drug administration to induce this response.However, the immune response to certain antigens may be inadequate, especially in the elderly.Additionally, adverse reactions from these antibodies may occur because of long-lasting response to antigens.