Production of a safe, potent and immunogenic partially purified acellular pertussis vaccine using simple indigenous techniques.

ABSTRACT

Partially purified acellular pertussis vaccine was prepared from Bordetella pertussis strains 10536, 134, Tohama and 509 using simple indigenously available techniques. The Stainer-Scholte (SS) medium with methylated-beta-cyclodextrin was the most suitable for production of acellular pertussis vaccine. For preparation of the vaccine, 5 day cultures of B. pertussis grown under stationary conditions at 35 degrees C were treated twice with ammonium sulphate and prospective protective antigens were extracted. The extracts contained pertussis toxin (PT), filamentous hemagglutinin and agglutinogens. These extracts were treated with formaldehyde and glutaraldehyde separately for detoxification of PT. The formaldehyde treatment of acellular preparations affected the potency and did not destroy the toxic effects of PT completely. Active PT was found in formaldehyde detoxified acellular pertussis vaccine (FDAPV) preparations by the Chinese hamster ovary (CHO) cell assay, the test for leucocytosis promoting factor (LPF) and the histamine sensitization (HS) test. The FDAPV preparations did not pass the mouse weight gain test (MWGT). The glutaraldehyde treatment had lesser adverse effects on potency than the formaldehyde treatment and the glutaraldehyde detoxified preparations did not show active PT by CHO cell assay, the test for LPF and the HS test. The mice tolerated high doses (up to four human doses) of GDAPV which passed the MWGT showing higher weight gains. Both FDAPV and GDAPV showed immunogenicity against agglutinogens and PT in mice. The GDAPV is a safe and potent vaccine. The total protein content of GDAPV was about 5 times lesser than that of whole cell pertussis vaccine.