Ostrich derived antibodies raised against the H5N1 hemagglutinin were impregnated into air filter media, and chickens behind that media were protected from aerosol H5N1 transmission. It is a proof of concept for filter media that act on the organism rather than only intercepting it.
Ouyang and colleagues placed approaches of this kind in their emerging category in 2023, alongside antimicrobial treated filters and electrostatic precipitation, distinct from the fibrous filtration that has a production record behind it. The distance from a controlled result to a barn installation is the issue with all of them. An antibody is a protein, and its activity depends on conditions that a laboratory holds steady and a barn does not, including temperature, humidity, contact time and the accumulating dust load that the carrier particle literature describes. The specificity that makes it work is also a constraint, since antibody raised against one hemagglutinin does not address other pathogens on the same air stream.
The reason to keep this work in view is what it suggests about direction rather than what it offers today. Mechanical filtration removes what it captures from the air and holds it, and Wenke and colleagues showed in 2017 that some captured organisms remain viable on the media for weeks. Media that inactivates rather than only retains would change what a filter change involves. That remains a research position, and a system specified now should be specified on mechanical performance.