Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Antimicrobial Surfaces For Pandemic Prevention?, published by Conrad K. on April 10, 2024 on The Effective Altruism Forum.

The next big research agenda in biosecurity? Or a flawed technology dead on arrival? Spoiler: it's somewhere in between.

Summary

I spent ~15-20 hours conducting research, holding expert interviews, and thinking through whether we should be excited about antimicrobial surfaces for pandemic prevention and, if so, what the next steps for this technology should be. Overall, I'm reasonably confident (~75%-80%) about the following but note it is highly oversimplified:

Antimicrobial surfaces inhibit the growth and spread of microorganisms. They can be categorised based on functional mechanism (antifouling, biocidal, hybrid), mode of action (chemically-functionalised, physical, biologically-functionalised, or composite), spectrum of effectiveness (targeted or broad-spectrum), and application (antimicrobial materials, pre-coating, or applied).

Research shows that antimicrobial surfaces can effectively kill microbes in the right conditions, but many unknowns remain regarding their efficacy outside lab settings, interactions between pathogens/surfaces/fomites, and use for mitigating pandemics.

Evidence is limited on antimicrobial surfaces preventing infections. Studies often have design issues and knowledge gaps remain regarding transmission mechanisms.

Little is established about the effectiveness of antimicrobial surfaces for mitigating pandemics. More research is needed on pathogen transmission routes, surface use cases, and cost-effectiveness.

Downsides include surface degradation over time, potential toxicity, inducing antimicrobial resistance, regulatory barriers, and high costs for novel technologies.

Antimicrobial surfaces are beginning to see more real-world use, with potential applications beyond infection control. The market for antimicrobial surfaces is growing.

Key open questions remain about the fundamentals of fomite transmission, interactions between pathogens and surfaces, surface degradation, accessibility, supply chain considerations, and ideal use cases.

Some reasons to be excited include reducing fomite transmission, continual action without reapplication, and multipurpose benefits. However, high costs, regulatory hurdles, concerns about antimicrobial resistance, and many research uncertainties are reasons for caution.

Overall, I lean towards it being worthwhile to resolve foundational questions about antimicrobial surfaces through (i) further testing and modelling; (ii) producing an ontology of surfaces, and (iii) conducting a detailed scoping of potential use cases for pandemic prevention.

Oxford Biosecurity Group will soon be running a project exploring producing an ontology of antimicrobial surfaces, and we're looking for a co-lead for this project. Reach out to us at [email protected] if you're interested.

What Are Antimicrobial Surfaces?

Antimicrobial surfaces are surfaces that are designed to inhibit the growth and spread of microorganisms, including bacteria, viruses, fungi, and algae. One way they can be categorised is as follows:

Functional Mechanism

Antifouling: surfaces that prevent microbial attachment and growth.

E.g. superwettable surfaces such as superhydrophobic modified aluminium or mussel-inspired superhydrophilic surfaces that work by either preventing microbial adhesion (hydrophobic) or creating a water barrier between microbes and the surfaces (hydrophilic).

Biocidal: surfaces that actively kill or inhibit microbes.

E.g. metals such as copper which release ions that kill microbes.

Hybrid: surfaces combining both antifouling and biocidal properties.

E.g. honeycomb-like patterned surfaces which trap bacteria, both preventing further growth and killing them.

Mode of Action

Chemically-functionalised: u...