THE CONTENT OF ANTIGENS 1,2 AND 3 IN STRAINS OF BORDETELLA PERTUSSIS AND IN VACCINES.

A comparison was made of the content of heat-labile antigens 1, 2 and 3 in strains of Bordetella pertussis isolated in Toronto, and the content of the same antigens in vaccines being used in that community. Antisera were prepared in rabbits and made monospecific by absorptions. Antigens were detected by slide agglutination tests. Of the 58 strains examined, 56 contained antigens 1 and 3 but no antigen 2 was detected. Nine of these strains were isolated from children who had received a full course of vaccination and had subsequently developed pertussis. All 10 vaccines examined contained antigen 1; two, possibly four, contained no antigen 2; and seven of the 10 vaccines were weak or deficient in antigen 3. This work suggests that improved protection might be attained by the use of vaccines containing adequate amounts of all three antigens.