The European Pharmacopoeia Commission (EPC) adopted a new general chapter, High-throughput sequencing for the detection of viral extraneous agents (2.6.41), during its 181st session in March 2025. The new chapter will be published in Issue 12.2 of the European Pharmacopoeia (Ph. Eur.) in October 2025 and will enter into force on 01 April 2026.
High-throughput sequencing (HTS, also known as Next-Generation Sequencing) is a state-of-the-art and sensitive molecular biology technology increasingly used to test for viral extraneous agents in biological products. In contrast to conventional tests used for this purpose, HTS can detect a broad range of viruses, both known and unknown. HTS also offers advantages over conventional methods in terms of animal welfare as it may be used instead of in vivo tests.
The new general chapter describes HTS methodologies used for the detection of viral extraneous agents in biological products, including vaccines, recombinant proteins, viral vectors used for gene therapy and cell-based preparations for cell therapy. It outlines the different steps in the HTS workflow, the design of the method (non-targeted and targeted HTS), analysis approaches (genomics, viromics and transcriptomics) and the controls used in the routine test. It also provides guidelines for HTS method validation, including recommendations for selecting spiking materials and the evaluation of the relevant performance characteristics for HTS, as well as product-specific validation.
High-throughput sequencing for the detection of viral extraneous agents was elaborated by an international group of experts comprising representatives of national competent authorities, national control laboratories and industry, and is intended to support users in implementing this new technology.
The new Ph. Eur. chapter on HTS, along with other regulatory standards (i.e. the revised ICH Q5A(R2) guideline that includes HTS and the WHO International Reference Panel for Adventitious Virus Detection by HTS), is a significant step towards the standardisation of HTS for the detection of viral contaminants.
Identified as a top priority for 2023-2025, the adoption of this general chapter demonstrates the EPC’s unwavering commitment to further modernising the Ph. Eur. and to replacing in vivo tests wherever possible.