A curious histamine-sensitizing activity shown by the newly-developed Japanese acellular pertussis vaccine

A new acellular pertussis vaccine, whose official name is "Precipitated Purified Pertussis Vaccine" (PPV), was prescribed in the Japanese Minimum Requirements for Biological Products in 1981. The PPV is composed of partially detoxified fractions of pertussis cells. The histamine-sensitizing (HS) activities of PPV vaccines are less than those of killed whole pertussis cell vaccines (WPV) produced in Japan until 1980, when the histamine challenge was carried out in mice on day four after injection. It was found that when the histamine challenge day was delayed that the HS activities of some lots of PPV gradually increased from those estimated on day four after injection of PPV and reached the maximum in about 12 days, while the activity of the reference whole cell pertussis vaccine reached the maximum several days after injection and then gradually decreased. Hereafter, HS activities of test materials estimated on days four and 12 after injection are referred to as early HS (EHS) and late HS (LHS) activities, respectively. Since LHS activity of the reference whole cell vaccine is lower than its EHS activity and the reverse is true with many lots of PPV, it is often observed that the EHS activity of PPV according to the Japanese requirement for PPV, ranges from 0.02 to 2.0 HSU whereas activities of some lots of PPV were estimated at 5.0 to 25.0 HSU. The relationship of the detoxifying process to EHS and LHS activities was studied with bulk materials, which were used for the purification procedure but prior to the detoxification process for the production of PPV.(ABSTRACT TRUNCATED AT 250 WORDS)