Objectives: Appropriately designed and adequately controlled quality control tests are a cornerstone of the pertussis vaccine regulatory program. Whole-cell pertussis vaccines have been adequately controlled by potency and toxicity tests defined by Federal Regulation; the Laboratory is responsible for maintenance of Standards for these tests. Acellular pertussis vaccines, on the other hand, represent a new product class for which there are no standardized and internationally-accepted methods for assessment of product potency and safety. With respect to quality control of pertussis vaccines, the Laboratory: a) Prepares and maintains standard materials for the control testing of pertussis vaccines. b) Standardizes the toxicity and immunogenicity tests employed for currently licensed acellular pertussis vaccines. c) Develops and evaluates new tests to assess the safety, purity, and potency of acellular pertussis vaccines. FY96 activities: 1. In the past year, the Laboratory performed 17 potency and 27 toxicity tests on vaccines containing a whole-cell pertussis component and 14 potency and 15 toxicity tests on vaccines containing a whole-cell pertussis component. 2. Participated in an international collaborative study for the proposed Third International Standard for Pertussis Vaccine [whole-cell]. Using the Second International Standard as a primary reference, completed 9 tests of the Proposed Third International Standard, 3 tests of a positive control vaccine, and 6 tests of the US Standard Pertussis Vaccine, Lot 11 and have submitted these data to the WHO coordinating center. 3. Initiated international distribution of US Standard Pertussis Antiserum (mouse]. Lot 1, a lyophilized serum with antibodies to PT, FHA, pertactin, and fimbriae previously prepared by the Laboratory of Pertussis. The serum serves as the primary standard serum for the mouse immunogenicity test for US-licensed acellular vaccines and has been selected as the primary standard for calibration of WHO and European Standards. 4. Using defined reagents and methods, a final validation study for the mouse immunogenicity test was conducted and is being used to determine intra-laboratory reproducibility and define assay validity criteria. Continued ongoing collaborative studies with all manufacturers pursuing US-licensure to assess the inter-laboratory reproducibility of the proposed immunogenicity assay. 5. Finalized the evaluation of the characteristics of several mouse strains in the histamine sensitivity test that is used as the final bulk toxicity test for acellular pertussis vaccines and defined assay validity criteria for this test. 6. Continued ongoing program to monitor CBER and manufacturer potency testing data of lots of whole-cell and acellular pertussis vaccines submitted for release. Data are analyzed to evaluate inter-laboratory reproducibility and to examine for temporal trends. 7. Two individuals from the laboratory were consultation committee members and wrote substantial portions of the first draft of the WHO Guidelines for the Production and Control of Acellular Pertussis Component of Monovalent or Combined Vaccines. Ongoing review led to the preparation of the final draft which has been submitted for action by the WHO Expert Committee on Biological Standardization.
