Precipitation with Antiserum as a Means of Estimating the Immunizing Value of Solutions of Pneumococcus Oral Vaccines

[摘要] The quantity of precipitate obtained on mixing a solution of pneumococcus vaccine (types 1 and 3) with antiserum appears to be a fairly reliable guide to its immunizing value when administered orally to white rats. This is ascribed to the important rôle which the soluble specific substance appears to have in oral immunization. The effects of feeding a given quantity of vaccine are not always distinguishable from those obtained when twice the amount is used. Such amounts are readily told apart by the precipitates which they yield. Lack of agreement between test tube and feeding results was observed where the method of concentrating the precipitable substance was such as to make it appear that the acetyl group (type 1) might be split off. The difficulties with type 3 are discussed. A preparation for which the immunizing dose for rats has been determined serves as a standard in the precipitation test.

[学科分类] 生物科学（综合）