Infectious asthma differs from extrinsic infection-triggered asthma in children. Only 25% of children who have asthma attacks associated with infection have true infectious asthma. In a doubleblind study with placebos, infectious asthma was treated by hyposensitization with large doses of mixed respiratory bacterial vaccine. There was significant statistical benefit in the vaccine-treated patients, and similar results were obtained in a larger longitudinal prospective study group with the method of paired data for controls. Indiscriminate use of such vaccines in asthma associated with infection is not justified and has less than one chance in four of being effective.
Mueller HL, Lanz M. Hyposensitization With Bacterial Vaccine in Infectious AsthmaA Double-Blind Study and a Longitudinal Study. JAMA. 1969;208(8):1379–1383. doi:10.1001/jama.1969.03160080043009