Adventitious Virus Testing
Detection of viral contamination within the manufacturing process and beyond.
What is Adventitious Virus testing and why is it important?
Adventitious agents such as viruses have the potential to contaminate and be amplified within the biomanufacturing processes. Such contamination has a number of entry points, from being introduced with raw materials, to events at final packaging. However, the highest risks come from raw materials of a biological origin (such as serum), and from amplification within the bioreactor. As there is the potential for these adventitious viruses to cause serious harm to patients, all manufacturers must adhere to strict GMP guidance and regulations to ensure that viral risk is mitigated.
Mitigation strategies for viral contamination within the manufacturing process revolve around the 3 pillars of prevention, removal and detection:
- Prevention of contamination is primarily through ensuring that all processes are isolated from common sources of viruses, e.g. operations staff. As raw materials are also a common source of viral contamination, these should be carefully selected and screened.
- Removal of both process and viral impurities occurs at downstream purification. The purification strategy, including filtration, pH treatments and chromatography are therefore assessed for their collective ability to remove virus in viral clearance studies. Other removal strategies could include treatment of higher risk raw materials (e.g. serum) and treatment of the final product to reduce virus risk.
- Detection of any contamination during manufacturing is also critical. As indicated, raw materials can be screened for viral risks, however, the regulators view the bioreactor as a particular risk as viruses have the potential to amplify from very low, undetectable levels, to levels that can present substantial hazard to the patient. Therefore, screening for adventitious viruses at this stage (referred to as bulk harvest) is a critical release step.
Traditional adventitious virus detection strategies use assays such as cell-based in vitro detection as well as in vivo models. The perceived advantage of these tests is that they can screen for both known as well as unknown viruses. However, the assays depend on the contaminating virus being able to amplify and have a demonstrable effect to allow for detection. Unfortunately, many viruses do not amplify within these systems. Further, some do amplify but do not cause any measurable effect on the cells or animals. As these methods can take weeks, or even months, they are often the pacing item for a batch to be released to the patient.
Another major drawback of in vivo and in vitro based detection is the compatibility of the test with the biopharmaceutical itself. If the drug has some toxicity, this can usually be dealt with by using a neutralizing antibody. However, such antibodies take many months to generate. Sometimes it is not even possible to generate a neutralizing antibody, making in vivo and in vitro testing impossible.
Molecular detection methods are typically insensitive to toxicity from the biologic to be tested, avoiding the need for a neutralizing antibody. These methods also tend to consume a lot less of the precious product. PCR is a common and highly sensitive test which is used to detect known and well characterized viruses. However, PCR will not detect viruses which are unknown, and may also struggle to detect known viruses where a genetic alteration has occurred. Dozens of PCR tests may also be required, consuming a lot of your precious product.
Using NGS as an approach for the detection of adventitious virus has a number of advantages. Like PCR it is insensitive to any potential toxicity. However, unlike PCR, NGS can sensitively detect both known as well as unknown or variant viruses. NGS is therefore an ideal viral detection strategy if there is an issue with antibody neutralization, or if speed and sample volumes are of particular concern.
What we do
Modalities Tested:
- mAbs and recombinant biologics
- Viral vectors
- Cell therapies
- Vaccines
- RNA based therapeutics
- Cultured meat
Benefits of NGS for Adventitious Virus Detection
✓
GMP validated✓
Faster results✓
Resolves assay compatibility issues✓
No need to generate neutralizing antibodies✓
Reduces overall sample requirement for precious material✓
Specific identification of contamination✓
Meet corporate 3Rs objectives by removing animal use
Comparison of Adventitious virus detection methods

WHY THIS APPROACH
ICH: Draft Guidline for Consultation Q5A (R2) viral safety evaluation of biotechnology products derived from cell lines of human or animal origin
FDA: Characterization and Qualification of Cell Substrates and Other Biological Materials Used in the Production of Viral Vaccines for Infectious
EMA: Guideline on the quality, non-clinical and clinical aspects of gene therapy medicinal products
FDA: Code of Federal Regulations, Title 21 Volume 7. Part 610 – General Biological Products Standards
SAMPLE REQUIREMENTS
PathoQuest has a number of approaches to adventitious virus detection that can depend on the source material and the desired outputs. We would therefore recommend having a consultation with one of our experts to discuss your exact requirements.
In general our sample requirements are:
- 5ml of harvest material (e.g. bioreactor or raw material)
- For viral seed stocks and cell bank samples (including cell therapy lots) please contact us
- Storage and shipment at -80°C or on dry ice
- Back up sample is recommended
Challenges solved
- Incompatibility of sample with traditional assays
- Very low sample volumes
- Tight clinical timelines
- Meeting corporate objectives for removing animal use
- Troubleshooting batch failures
- Identification of contamination source
OTHER SERVICES
Identity Confirmation
Genetic characterization of viral and plasmid products for release.
READ MORE

nCats Integration Site Analysis
Characterisation of genetic modifications for clone selection, genetic stability and lot release
In Vivo Replacement
NGS as an ethical alternative to animals in biosafety testing and characterization.
READ MORE
Cell Line Characterization
Biosafety screening and stability testing of manufacturing cells.
READ MORE
HLA Genotyping
Characterizing and screening for novel and emerging cell therapies.
READ MORE
Raw Material Testing
Screening of high-risk inputs such as animal products and media.
READ MORE
Contact us
U.S.
466 Devon Park Dr
Wayne, PA 19087
United States
E: contact@pathoquest.com
Sign up for our latest news
France
+33 (0)1 70 82 17 90
Biopark -Bâtiment B,
11, rue Watt
75013 Paris, France
How can PathoQuest help?
U.S.
466 Devon Park Dr
Wayne, PA 19087
United States
France
+33 (0)1 70 82 17 90
Biopark -Bâtiment B,
11, rue Watt
75013 Paris, France
E: contact@pathoquest.com
How can PathoQuest help?
Sign up for our latest news