ACTIVE IMMUNIZATION AGAINST SECONDARY BACTERIAL INFECTIONS OF THE COMMON COLD: Production of Protective Antibodies in Human Adults by the Oral Administration of Stock Polyvalent Bacterial Vaccines

AS PREVIOUSLY reported, 1 the oral administration to mice of stock polyvalent vaccines prepared from the desiccated organisms and their soluble products commonly involved in the secondary bacterial infections of the common cold has been found effective in the active immunization of some of these animals against virulent hemolytic streptococci, pneumococci of types I, II and III, Klebsiella pneumoniae and Staphylococcus aureus. The investigations of Thomson and Thomson 2 have also shown that such vaccines may be absorbed after oral administration to human beings, in whom agglutinins are then produced. Ross 3 has likewise found that the oral administration of vaccines of pneumococci to human beings not only is well borne but quickly produces immunity, since protective antibodies against the type I pneumococcus were found in the serums of 75 per cent of subjects and against types II and III pneumococci in the serums of about 60 per cent. Thomson.