Rapid, Automated, At-Line Adenovirus Quantitation

By Thomas Kruse, Timo Königsmann, Alexander D Douglas, Carina Joe, Ivan Krylov, Yuanyuan Zhang, David Apiyo, Julia Niemann, and Markus Kampmann

Viral vector vaccines provide a fast and effective response to emerging pathogens, including applications in personalized cancer therapies. Adenoviruses (AV), known for their versatility and extensive clinical use, are one of the most well-characterized viral vectors. Their proven safety, and ability to induce strong and long-lasting immune responses, comprising both humoral (antibody) and cellular (T-cell), make them especially valuable. Notable examples of adenoviral vector vaccines include the COVID-19 vaccines developed by Oxford/AstraZeneca and Johnson & Johnson. However, significant challenges remain in the analytical methods used for the development and production of adenoviral biopharmaceuticals, which require ongoing improvements to enable more reliable and efficient vector quantification and functional evaluation.

While viral genomes are quantified through qPCR, ddPCR, or optical methods like OD260nm, the capsid titer is typically measured via ELISA. Additionally, analytical ultracentrifugation (AUC) is often employed to differentiate between empty and full capsids. These techniques, though effective, can be time-consuming and labor-intensive, making them less suitable for rapid, at-line viral titer measurement during development and manufacturing. In this application note, the development of a high-throughput capsid assay for rapid AV quantification is presented. This new assay utilizes the Octet® BLI platform, which offers high precision and reliability when compared to qPCR measurements. Further, the assay can be applied as a standardized method for at-line viral titer quantification in bioprocess settings.