Antipneumococcic serum, as developed by Neufeld, was not regarded as entirely satisfactory as a therapeutic agent. Cole and his co-workers renewed the interest in this serum, however, by their work on the differentiation of types of pneumococci and the application of the specific univalent serums.
Clinical evidence has since accumulated which tends to encourage the use of Cole's Type I serum in cases in which the corresponding type of infecting organism has been determined.
The official control of this product by protection tests has thus far been confined to serum produced by the immunization of horses against Type I pneumococci.
Polyvalent serums are required to show the same protective action against Type I organisms as is the specific type serum.
The evidences of the manufacturers' protection tests are accepted for the potency of serums made by immunizing animals against pneumococci of Types II and III.
The present method of testing
WAYSON NE, McCOY GW. THE POTENCY OF ANTIPNEUMOCOCCIC SERUM. JAMA. 1918;70(23):1747–1749. doi:10.1001/jama.1918.02600230017004