The Mycoplasma Gallisepticum bacterin vaccine, often referred to as MG-BAC vaccine, is used to treat chronic respiratory disease (CRD). CRD is caused by Mycoplasma gallisepticum, a bacterium that affects the respiratory system of poultry, including chickens, turkeys, geese and ducks. The disease affects farmers in Bogor, Yogyakarta, Malang, Surabaya and Bali in Indonesia. The pattern of transmission from the mother involves bacterial contamination of the cage environment, contact between sick and healthy birds through food and drink, and infection through the mother’s eggs.