TiO2 Photocatalyst Inactivates Highly Pathogenic Avian Influenza Virus and H1N1 Seasonal Influenza Virus via Multi-Antiviral Effects

The highly pathogenic avian influenza virus (HPAIV) is widely distributed worldwide and causes significant economic losses. Transmission of HPAIV occurs through direct contact between infected and susceptible birds or indirectly via contaminated materials. In recent years, airborne transmission of HPAIV has also been reported, underscoring the need for novel approaches to effectively inactivate airborne HPAIV. Photocatalysts have attracted significant attention as potential antiviral agents. In this study, we demonstrated that a TiO2-mediated photocatalytic reaction inactivated HPAIV and H1N1 seasonal influenza viruses in liquid, reducing their infectivity by 90.7% and 94.4%, respectively, after 60 min. Mechanistic analyses revealed decreased virion size and surface structure disruption, as determined by transmission electron microscopy. Additional evidence of viral protein and genome damage was obtained using Western blotting and RT-qPCR, respectively. Given the broad antiviral activity of photocatalysts, these findings suggest that they can inactivate influenza viruses regardless of strain or subtype. Notably, photocatalysts inactivated 80% of aerosolized H1N1 seasonal influenza viruses within 5 min. These results provide strong evidence that photocatalysts are capable of inactivating airborne influenza viruses. This study represents the first demonstration that photocatalysts can inactivate HPAIV and aerosolized influenza viruses. These findings provide strong evidence that photocatalysts represent a promising countermeasure against HPAIV, with potential applicability across different strains and subtypes.