Establishment of mouse neutralizing antibody detection method as potency assay for acellular pertussis vaccines / 中华微生物学和免疫学杂志

ABSTRACT

Objective@#To establish a functional antibody detection method for acellular pertussis vaccines in order to conveniently and effectively evaluate the production consistency and potency of acellular pertussis vaccine bulks and final products.@*Methods@#Chinese hamster ovary (CHO) cell clustering assay was optimized and used to measure titers of neutralizing antibodies against pertussis toxin in mouse immune serum samples.@*Results@#Vaccine samples were determined to be immunized intraperitoneally with 1/5 the human dose to ten female NIH mice (20-24 g, 5-week-old). Four weeks after immunization, blood samples were collected to isolate serum. Serially diluted serum samples were used to neutralize 0.1 IU/ml of pertussis toxin national reference product for 2 hours. Results of clustering were determined after 48 hours of incubation in pre-cultured CHO cell wells. The geometric mean of the serum dilution of the final unclustered wells was the neutralizing antibody titer of vaccine sample. There were significant differences in the titers of neutralizing antibodies elicited by acellular pertussis vaccines prepared with different manufacturing processes. Vaccine samples succeed or failed the modified intracerebral challenge assay (MICA) were easily distinguishable by neutralizing antibodies.@*Conclusion@#The method of detecting neutralizing antibodies to pertussis toxin greatly reduces the amount of animals used in research. CHO cell clustering assay that has better repeatability and precision can be used for monitoring and initial evaluation of the consistency and potency of the bulks and final products of pertussis vaccines prepared with different manufacturing processes.