Roadmap for the development of disease control strategies for coronaviruses

Download 202410 Draft Coronavirus Disease control research roadmap Final

Pathogen inactivation

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Pathogen inactivation

Research Question

Develop and validate standardised and accessible methods to inactivate virus in farming, domestic and wildlife settings

Research Gaps and Challenges

Understanding the persistence of different viruses on different surfaces and how much log reduction is needed to prevent transmission. This feeds into the challenge of identifying standards for declaring pathogen free status in the environment and on farms
Identifying the most effective methods for inactivating different strains in the field to ensure safe handling protocols and procedures for sample collection
We currently have incomplete data on the comparative effectiveness of inactivation methods (e.g., heat, chemicals, UV light) across different coronavirus strains, host species and contexts. Further study into the applicability in farm and wildlife settings is needed
Current approaches to validate inactivation may rely on molecular diagnostics to detect viral nucleic acids, however this is flawed due to the lack of differentiation between the presence of infectious and historic viruses. Improvement to diagnostics testing should introduce diagnostics of active replication and these tests need to be implemented widely
Due to the limitations of molecular testing, current approaches also require viral isolation to prove a presence/absence of infectious virus. Therefore, achieving regulation and approvals for pathogen inactivation methods requires access to- and expertise in BSL3/CL3/SAPO for safe handling and process validation
Local policies, external stakeholder perceptions and in-country legislation will affect the acceptability of the proposed methods leading to variability. A global co-ordinated effort is needed to standardise methods for wider implementation
Moving away from using animals in experimental work due to a lack of species-specific resources, cost, animal welfare/ethical considerations, the requirement for relevant expertise and facilities. We need new cell systems for investigations of this sort; however, consideration should be given to the emergence of lab adaptions in viral isolates which may affect viral kinetics and response to inactivation and therapeutics

Solution Routes

Developing new tools e.g. pseudoviruses, that bypass the need to work under SAPO/BSL3/CL3 containment
Developing and optimising tools to inactivate virus by air system (i.e. UV power per different airflow)
Study the influence of environmental factors e.g. temperature, humidity, and surface type, on the efficacy of inactivation
Modelling of inactivation methods in real setting.
Study environmental impact and safety of inactivation methods
Develop standardized protocols to ensure consistent inactivation rates and safety across different settings
Exploring alternative methods of pathogen-inactivation e.g. composting, which occurs in low- and middle-resource settings

Dependencies

The establishment and validation of standardised methods to measure virus inactivation and clarification on which gold-standard test to use to demonstrate negative result given that molecular testing can give positive results but do not infer live viruses. This is particularly important for farming practices following outbreak where access to laboratory testing may be constrained. Consideration could be given the expanding on the use of sentinel animals more widely.

State Of the Art

Single pass UVC air treatment (1254 L/min) can effectively inactivate bovine coronavirus (2.4-log reduction). (Snelling, W. J., Afkhami, A., Turkington, H. L., Carlisle, C., Cosby, S. L., Hamilton, J. W. J., Ternan, N. G., & Dunlop, P. S. M. (2022). Efficacy of single pass UVC air treatment for the inactivation of coronavirus, MS2 coliphage and Staphylococcus aureus bioaerosols. Journal of Aerosol Science, 164, Article 106003). https://pure.ulster.ac.uk/ws/portalfiles/portal/101170681/1_s2.0_S0021850222000477_main_1_.pdf