A two-year double-blind control study to determine the effectiveness of bacterial-vaccine therapy was performed on 30 children with infectious asthma. The first year, from October to April, all the children received buffered saline injections weekly. Symptom cards were kept by the family during the two year study. The second year, the children were randomly divided into two groups, one receiving a bacterial vaccine, the other a placebo solution. A reduction in the incidence of wheezing, infection, and infectious episodes associated with wheezing was observed in a larger percentage of the placebo group than in the vaccine-treated group. The amount of antiasthmatic medication administered during the first and second years was equivalent.