Autogenous vaccines provide an alternative way to induce immunity in animals without paying expensive fees for unnecessary vaccine strains. The mechanism of action of autogenous vaccine is not fully understood, however, it is suggested that it involves activation of the innate immune system to produce a nonspecific immune response and activation of the adaptive immune system to produce a specific immune response. Following the injection, the innate immune system is activated and sends large amounts of phagocytes to the injection site which kills the microorganisms. Phagocytes will then present the antigens to T helper cells to activate the adaptive immune system. T helper cells activate macrophages and neutrophils to aid in killing the pathogenic microorganisms. T helper cells also aid plasma cells to produce antibodies, thus allowing the immune system to “remember” the vaccine agents. As the surface antigens in the vaccine are the same as those of the disease, the immune system can recognise the pathogenic agents and produce an immune response to kill them when the pathogen is encountered. Autogenous vaccine production usually occurs when there is such a demand. In human beings, samples of pathogens are isolated from a site of infection in the sick individual, for instance pus or abscess, sputum, urine and vaginal discharge. The identified pathogenic agents will then be cultured and inactivated, either by chemicals or by heat. The inactivation process involves the destruction of the antigen activity while preserving the protein composition of it, as the state of the protein can affect the effectiveness of immune response in the patient. Tests will then be conducted to ensure the sterility, safety and quality. The whole manufacturing process can take up to 3 to 4 weeks depending on the manufacturer. In animals, the preparation is similar. An example of this is when an infectious disorder is discovered in a farm herd. This discovery prompts the veterinarian to take samples from infected animals. These samples will then be delivered to a laboratory for culture and isolation of the pathogenic agents. Once the pathogenic agents are identified, they can be used to manufacture vaccines. This is followed by a series of steps to formulate the desired product and ensure its quality and safety. The formulated vaccine is then delivered back to the veterinarian where the vaccine will be administered to the herd. Before the formulated vaccine is administered to the patient, the patient receives an intradermal skin test to ensure the patient does not have any hypersensitivity reactions to the vaccine. Once the test is conducted and proven negative, treatment can begin. The autogenous vaccine is applied subcutaneously in intervals over weeks or months.