Human pathogens can persist on textiles and high-traffic surfaces for hours, days or even longer when protected in biofilms, increasing risk of infection spreading. Conventional cleaning has no lasting effect as contamination can re-occur almost immediately. Available antimicrobial coatings are based mainly on the release of silver ions and other biocides that present risks for resistance development and environmental damage. Inorganic nanoparticles are also a concern for human health. Nanocellulose is a versatile nanomaterial obtained from wood pulp or biotechnological methods, which has excellent physical properties for coatings, enabling controllable and standardised application of antimicrobial functionalities. In Triple-A-COAT the 3 forms of nanocellulose will be augmented for antimicrobial/antiviral activity through grafting/adsorption of novel, resistance-proof compounds with excellent activities against bacteria, fungi and/or viruses, and nanopatterning to create bio-inspired antimicrobial surfaces. Spray coating and thin film applications will be developed, optimising adherence to plastic, metal, textiles and glass. The most effective coatings will be evaluated for antimicrobial/antiviral activity, durability and non-toxicity using ISO standard tests, and in a simulation of a bus environment over 6 months to reach TRL6. A life cycle assessment of the platform will also be completed. The project consortium involves companies, academic and SME partners with leading expertise in novel antimicrobial and antiviral technology, nanocellulose production and functionalisation, coatings development and characterisation, as well as a bus manufacturer and an external User Committee. Within 5-10 years after the end of the project, the results will be commercialized for impact in the transportation and healthcare sectors, contributing to the better control of infectious disease, and boosting the competitiveness and research leadership of EU industry including SMEs.