Why are viral safety practices the way they are today? What risks, scientific discoveries, and regulatory updates caused them to develop as they have? This timeline highlights the milestones that created the viral safety standards used today. Throughout that evolution, Minaris Advanced Testing has been at the forefront, advancing the methods that make viral safety reliable, repeatable, and trusted.
1960
SV40 contamination identified in polio vaccines
Sweet & Hilleman (1960) and subsequent analyses document simian virus 40 (SV40) contamination of poliovirus vaccine lots produced in primary monkey kidney cells, driving early awareness of adventitious-agent risks in cell-substrate–derived medical products.1
1973
Endogenous retroviruslike particles (RVLPs) discovered in CHO cells
CHO cells, which later became the dominant host for recombinant biologics, are shown to secrete C-type and A-type retrovirus-like particles. Although non-infectious, their presence establishes the need for viral-clearance steps in recombinant biologics.2
Early
1980s
to Mid
1985
Solvent/Detergent (S/D) viral inactivation developed and adopted
S/D treatment (e.g., TnBP + detergents) is developed in the early 1980s and fully adopted by 1985 for plasma-derived products, transforming safety against lipid-enveloped viruses (HIV, HBV, HCV) and influencing viral-inactivation strategy in biologics more broadly.3
Late
1980s
(≈ 1988)
Low-pH incubation validated for viral inactivation in IVIG; later adopted for mAbs
Studies show pH ~4 incubation (with or without pepsin) inactivates enveloped viruses including HIV, HSV, VSV, and CMV. Low-pH hold becomes a canonical viral-inactivation step in recombinant protein processes, especially monoclonal antibodies.4
1982
ViroMed Founded
Pioneer in early viral safety testing and clinical virology, including the use of qPCR to detect viral contamination.
1989
Virus-filtration (nanofiltration) commercialized (e.g., Planova filters)
Asahi Kasei introduces Planova virus-removal filters (~1989), enabling robust size-based removal of small viruses. Filtration becomes a core orthogonal viral-clearance unit operation.5
1990s
Real-world failures reveal limits of single-step inactivation
Transmission events involving non-enveloped and acid-resistant viruses in plasma-derived immunoglobulins highlight the inadequacy of relying on a single inactivation step, driving industry toward multilayered removal/inactivation strategies.6
9/24
1998
ICH Q5A (original) published
ICH Q5A establishes harmonized global expectations for biotechnology products produced in mammalian cells, including cell-bank testing, adventitious-agent testing, and validation of viral-clearance studies (removal + inactivation).7
2000s
Viral-clearance frameworks extended to CHO-derived recombinant proteins
As CHO endogenous RVLPs remains a known intrinsic risk, recombinant-mAb and protein processes standardized pH hold, virus filtration, chromatography depyrogenation steps, and validated multistep viral-clearance packages.
2001
ViroMed acquires Axios and Quality Biotech
A new testing site is opened in St. Paul, MN, expanding the company’s viral vector expertise, bringing to three the total number of sites in the company.
ViroMed Reorganized as AppTec
2008
AppTec acquired by WuXi Pharmtech, becomes WuXi AppTec
Scales into leading provider of viral safety studies for the industry.
3/15
2010
Porcine circovirus (PCV) DNA detected in Rotarix vaccine
PCV-1 DNA is identified via deep sequencing in Rotarix and later PCV sequences are found in Rotateq. Regulators and manufacturers re-evaluate raw materials, cell substrates, and modern molecular detection methods.8
10/25
2012
EMA approves Glybera, the first gene therapy in the EU
Glybera’s AAV vector marks the first marketed viral-vector gene therapy, raising new regulatory considerations around replication-competent AAV (rcAAV), helpers, producer-cell contamination, and viral clearance for vectors.9
2016
USP (1050.1) published
The United States Pharmacopeia introduces General Chapter 1050.1 to provide detailed, practical guidance on the design, execution, and interpretation of viral clearance studies, complementing ICH Q5A by standardizing approaches to virus selection, study controls, and data evaluation in biologics manufacturing.10
12/19
2017
FDA approves LUXTURNA (AAV)
First U.S. approval of an AAV gene therapy. Places additional regulatory focus on vector-production systems (triple transfection, helper viruses, baculovirus/Sf9 systems) and appropriate viral-safety testing strategies.11
2018
WuXi AppTec spins out WuXi Advanced Therapies
This spinout creates a standalone manufacturing and testing business focused on cell and gene therapies.
5/24
2019
FDA approves ZOLGENSMA (AAV)
Large-scale viral-vector manufacturing highlights the limits of classical clearance approaches and increases attention to testing for helper viruses, producer-cell impurities, and adventitious agents in high-titer AAV processes.12
2020
WuXi Advanced Therapies assists with COVID-19 response
Wuxi Advanced Therapies partners to support several antibody treatments for SARS-COV2, ensuring viral safety along with other aspects of development.
11/1
2023
ICH Q5A(R2) final text published
Major update to viral-safety expectations: expands virus-selection guidance, platform/ prior-knowledge use, considerations for viral-vector products, continuous manufacturing, and endorsement of modern molecular assays (e.g., NGS, PCR-based methods).13
1/10
2024
FDA issues Q5A(R2)aligned final guidance
FDA harmonizes with ICH Q5A(R2), emphasizing risk-based approaches, advanced detection methods, and updated expectations for viral-vector and continuous-manufacturing platforms.14
6/14
2024
Q5A(R2) becomes effective in the EU.15
2025
WuXi AppTec. / Advanced Therapies merges with Minaris Regenerative Medicine, becomes Minaris
Wholly US-owned business headquartered in Philadelphia combines CDMO for advanced therapies with Advanced Testing organization focused on biologics (protein therapeutics, cell therapies, viral vectors, and vaccines).
2026
& beyond
As biologic therapies become more advanced and ICH Q5A(R2) reshapes regulatory expectations, viral safety continues to evolve. Minaris Advanced Testing continues to advance the science of viral detection and clearance, serving the biotechnology industry to ensure the latest techniques are applied efficiently in safety studies. Find out how we do it and start a conversation at minaris.com/all-testing-services/viral-clearance/
References:
- Sweet BH, Hilleman MR. The vacuolating virus, SV40. Proc Soc Exp Biol Med. 1960;105:420-427.
- Lieber MM, Benveniste RE, Livingston DM, Todaro GJ. Mammalian cells in culture frequently release type C viruses. Science. 1973;182(4115):56-59.
- Horowitz MS, Rook AH, Horowitz B, et al. Virus inactivation in labile blood derivatives. I. Disruption of lipid-enveloped viruses by tri(n-butyl) phosphate detergent combinations. Transfusion. 1985;25(6):516-522.
- Barrett PN, et al. Inactivation of viruses in immunoglobulin preparations by low pH. Vox Sang. 1988;55(2):92-98.
- Burnouf T. Modern plasma fractionation. Transfus Med Rev. 2007;21(2):101-117. (Includes historical discussion of nanofiltration introduction, including Planova filters.)
- Centers for Disease Control and Prevention (CDC). Outbreaks of hepatitis A associated with clotting factor concentrates. MMWR Morb Mortal Wkly Rep. 1996;45:29-33.
- International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). Q5A: Viral Safety Evaluation of Biotechnology Products Derived From Cell Lines of Human or Animal Origin. September 24, 1998.
- Victoria JG, Kapoor A, Li L, et al. Metagenomic analyses of viruses in vaccines reveal the presence of porcine circovirus 1. J Virol. 2010;84(12):6033-6040.
- European Medicines Agency (EMA). Glybera: EPAR – Public assessment report. Approved October 25, 2012.
- United States Pharmacopeia (USP). General Chapter (1050.1) Viral Clearance. USP 39–NF 34. Published 2016.
- US Food and Drug Administration (FDA). FDA approves novel gene therapy to treat patients with a rare form of inherited vision loss (LUXTURNA). December 19, 2017.
- US Food and Drug Administration (FDA). FDA approves innovative gene therapy to treat pediatric patients with spinal muscular atrophy (ZOLGENSMA). May 24, 2019.
- International Council for Harmonisation (ICH). Q5A(R2): Viral Safety Evaluation of Biotechnology Products Derived From Cell Lines of Human or Animal Origin. Final Step 4 version. November 1, 2023.
- US Food and Drug Administration (FDA). Q5A(R2) Viral Safety Evaluation of Biotechnology Products Derived From Cell Lines of Human or Animal Origin; Guidance for Industry. January 2024. Federal Register. 2024;89:1925.
- European Medicines Agency (EMA). ICH Q5A(R2).