Something over a year ago we reported a series of controlled studies of several vaccines which are advocated for the prevention of colds. One of these was a mixed bacterial vaccine for subcutaneous administration, the organisms in which were destroyed mechanically instead of by heat. The other two vaccines were of the type recently developed for oral administration. The results of these studies were summarized as follows:1
In a carefully controlled study of the value of three different vaccines which are recommended for the prevention of colds the subjects were cold-susceptible students of the University of Minnesota.
A "control group" was observed during each year of the study. Such groups were chosen at random from the students who applied for cold prevention treatment; the members were treated in exactly the same manner as those of the vaccinated groups, and they believed throughout the period of the experiment that
DIEHL HS, BAKER AB, COWAN DW. COLD VACCINESA FURTHER EVALUATION. JAMA. 1940;115(8):593–594. doi:10.1001/jama.1940.02810340021007