A robust approach for the quantitation of viral concentration in an adenoviral vector-based human immunodeficiency virus vaccine by real-time quantitative polymerase chain reaction.
A real-time quantitative polymerase chain reaction (PCR)-based method was developed to measure the concentration of recombinant adenoviral vector genomes in purified virus bulks and final container samples of monovalent and multivalent human immunodeficiency virus (HIV) adenoviral vector vaccine candidates. This method, referred to as the genome quantitation assay (GQA), was optimized through a rigorous approach for evaluating PCR detection chemistries, designing a robust assay format, and establishing a properly calibrated reference standard. In addition, the use of a simplified lysis procedure, automated liquid transfer system, and parallel-line data analysis contribute to an accurate, precise, reliable, and high-throughput assay procedure that can be used for process monitoring, final formulation, and release of vaccine products. A variance component analysis study indicated that the GQA typically produces results with an interassay precision of less than 10% relative standard deviation (RSD), allowing generation of final results (average of three runs) with associated interassay precision of 6% RSD or less. The precision, accuracy, specificity, and robustness of the GQA demonstrate its utility for analytical characterization of a wide variety of viral vector- and DNA plasmid- based vaccines or gene therapy products. In addition, we also evaluated the Adenovirus Reference Standard generated by the Adenovirus Reference Material Working Group in the GQA to provide a common point-of-reference for our analytical method.