A method of manufacturing a vaccine composition containing antigen extracted from pig tissue infected with a complex respiratory disease is provided to prevent and treat a post weaning multisystemic wasting syndrome(PMWS) and a pig respiratory organ complex syndrome(PRDC). A method of manufacture the vaccine composition comprises steps of: i) removing pig tissue infected with a complex respiratory diseases; ii) extracting antigen by adding a solution comprising a glycine buffer solution and triton X-100 of 0.5% to the tissue; and iii) being inactivated by a formalin.
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