Understanding how an oncolytic herpesvirus (oHSV) or any HHV-derived therapeutic vector behaves within the host is essential for ensuring safety and efficacy. At CD BioSciences, we provide comprehensive biodistribution and viral shedding studies designed to characterize the in vivo fate, tissue tropism, and potential environmental transmission of viral candidates. These studies form a critical component of pre-clinical development packages, supporting regulatory submissions and risk assessments before first-in-human studies.
Our team combines deep expertise in herpesvirus biology, advanced molecular quantification technologies, and GLP-like animal study design to deliver accurate, reproducible data that de-risks your oncolytic virus or gene therapy program.
Importance of Biodistribution and Shedding Assessments
For HHV-based oncolytic and gene therapy vectors, understanding biodistribution and shedding patterns is crucial to:
- Evaluate Safety – Determine off-target tissue localization and potential unintended infection or persistence.
- Characterize Pharmacokinetics of Viral Replication – Understand viral replication kinetics and clearance in specific organs.
- Assess Environmental Risk – Evaluate whether the virus can be released from the host (shedding) through excreta or secretions.
- Support Regulatory Submissions – Meet FDA and EMA expectations for pre-clinical viral safety and biodistribution studies.
- Inform Dose and Delivery Strategies – Guide optimization of administration routes and therapeutic regimens.
For herpesvirus-derived platforms, such as engineered HSV-1 or KSHV vectors, these evaluations are indispensable to understanding latent infection potential and host immune response modulation.
Our Expertise in HHV Biodistribution Studies
CD BioSciences provides end-to-end biodistribution testing tailored for HHV-based therapeutic candidates, from study design to data interpretation.
1. Study Design and Experimental Planning
We design scientifically justified and regulatory-compliant protocols that align with FDA/EMA guidelines and ICH S6(R1) recommendations. Our study design includes:
- Selection of appropriate animal species and sample size based on viral tropism and host susceptibility.
- Determination of administration route (intratumoral, intravenous, intraperitoneal, or intranasal) according to intended clinical use.
- Definition of sampling schedule to capture peak replication and clearance phases.
- Integration of control and mock-treated groups for background correction.
2. Tissue Collection and Quantification
We systematically collect and analyze samples from major organs (brain, liver, spleen, kidney, lung, heart, reproductive organs, lymph nodes, and tumor tissue) at defined timepoints.
Detection and quantification approaches include:
- qPCR / ddPCR – High-sensitivity detection of viral genomes to determine tissue distribution and clearance kinetics.
- Plaque Assay / TCID50 – Measurement of replication-competent viral titers.
- Immunohistochemistry (IHC) – Localization of viral proteins within tissues.
- In Situ Hybridization (ISH) – Visualization of viral nucleic acids in target cells.
- Bioluminescence Imaging (BLI) – Real-time tracking of viral dissemination when reporter constructs are included.
Viral Shedding Analysis
While biodistribution studies assess viral presence within the host, viral shedding studies evaluate possible release into the environment or transmission to contacts. Our shedding evaluation strategy is designed for herpesvirus-based therapeutics, which can establish latency or reactivate under specific conditions.
1. Sample Types and Collection
We collect and analyze excretory and secretory samples, including:
- Nasal, oral, and ocular swabs
- Blood, urine, and feces
- Saliva and semen
- Vaginal secretions and skin lesion exudates
2. Analytical Techniques
- Quantitative PCR (qPCR/ddPCR): Detects viral DNA or RNA copies.
- Infectivity Assays: Identifies viable, replication-competent viral particles.
- Neutralization Studies: Assesses potential reduction of shedding through immune response.
- Duration and Frequency Analysis: Determines the time window and persistence of shedding events.
3. Data Interpretation
Comprehensive reports summarize viral detectability, tissue-specific persistence, and potential transmission risk. The data generated contribute to environmental risk assessments and biosafety dossiers required by regulatory authorities.
Applications for HHV-based Therapeutics
Our biodistribution and shedding studies are applicable to a wide range of HHV-related viral therapies, including:
- Oncolytic HSV-1 vectors (oHSV): Characterization of tumor selectivity, replication, and systemic spread.
- KSHV- or EBV-derived viral vectors: Evaluation of latency potential and tissue persistence.
- HHV-based gene therapy vectors: Verification of delivery efficiency and off-target distribution.
- Recombinant vaccine vectors: Understanding local immune activation and viral clearance.
Each program is customized to address the biological features of the specific herpesvirus backbone and its genetic modifications.
Technological Platforms Supporting Our Studies
CD BioSciences integrates multiple analytical platforms to provide multi-layered data precision:
| Platform | Description |
| Molecular Quantification | qPCR, ddPCR, and next-generation sequencing for quantitative genome detection. |
| Histopathology & Imaging | IHC, ISH, and fluorescence microscopy for spatial localization. |
| Virological Assays | Plaque assay, viral outgrowth, and infectivity testing for replication competence. |
| Immunological Profiling | Cytokine assays and flow cytometry for host immune monitoring. |
| Bioinformatics Analysis | Integrated kinetic modeling and heatmap visualization for viral spread patterns. |
These platforms ensure comprehensive characterization of viral biodistribution and shedding with high accuracy and reproducibility.
Why Choose CD BioSciences
1. HHV-Focused Expertise
Our scientists specialize in human herpesvirus biology, with experience spanning HSV-1/2, VZV, EBV, KSHV, and CMV. This focus enables us to interpret complex results and provide virus-specific insights that general CROs may overlook.
2. Regulatory-Ready Study Packages
Our study reports are formatted to support IND-enabling submissions in accordance with ICH, FDA, and EMA guidelines, including full datasets, raw data summaries, and methodological details.
3. Integrated Development Support
Beyond biodistribution and shedding, we offer seamless integration with viral engineering, in vitro/in vivo oncolytic activity assessment, and immune profiling services — enabling clients to consolidate their entire pre-clinical program under one partner.
4. Data Integrity and Confidentiality
All projects are conducted under strict data governance protocols to ensure reproducibility, traceability, and client confidentiality.
Workflow Example
- Consultation and Study Design – Define viral type, administration route, and sampling schedule.
- In Vivo Study Execution – Dosing, monitoring, and sample collection.
- Analytical Testing – qPCR, IHC, and infectivity assays.
- Data Processing & Bioinformatics – Viral load analysis and visualization.
- Final Report Delivery – Comprehensive documentation with interpretation and recommendations.
Deliverables
- Study protocol and rationale
- Raw and processed data tables
- Biodistribution maps and kinetics charts
- Shedding analysis summary
- GLP-style study report suitable for regulatory submission
Partner with CD BioSciences
CD BioSciences is dedicated to accelerating HHV-based therapeutic innovations by providing robust, data-driven viral biodistribution and shedding evaluations. Our integrated scientific expertise, advanced analytics, and quality-driven approach empower our clients to confidently advance their pre-clinical programs toward regulatory approval.
Whether your program focuses on oncolytic herpesvirus development, HHV-derived gene therapy vectors, or attenuated vaccine constructs, our team ensures every aspect of viral distribution and clearance is characterized with precision and reliability.
Contact us today to discuss your HHV biodistribution and viral shedding study needs — and experience the CD BioSciences commitment to scientific excellence.
References
- FDA Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy Products. U.S. Food and Drug Administration, 2013.
- EMA Guideline on the Quality, Non-clinical and Clinical Aspects of Gene Therapy Medicinal Products. EMA/CHMP/GTWP/671639/2008.
- MacDonald, M. et al. Biodistribution studies of oncolytic herpes simplex virus vectors: considerations for vector design and safety evaluation. Mol Ther Oncolytics, 2021; 21: 240–252.
- Studebaker, A.W., et al. Viral shedding and biodistribution studies for oncolytic HSV-based therapies. Hum Gene Ther Clin Dev, 2020; 31(2): 95–108.
- ICH S6(R1): Preclinical Safety Evaluation of Biotechnology-Derived Pharmaceuticals. International Council for Harmonisation, 2011.