Intranasal antisepsis to reduce influenza virus transmission in an animal model

Seasonal influenza annually causes significant morbidity and mortality, and unpredictable respiratory virus zoonoses, such as the current COVID-19 pandemic, can threaten the health and lives of millions more. Molecular iodine (I₂ ) is a broad-spectrum, pathogen-nonspecific antiseptic agent that has demonstrated antimicrobial activity against a wide range of bacteria, virus, and fungi.

We investigated a commercially available antiseptic, a non-irritating formulation of iodine (5% povidone-iodine) with a film-forming agent that extends the duration of the iodine's antimicrobial activity, for its ability to prevent influenza virus transmission between infected and susceptible animals in the guinea pig model of influenza virus transmission.

We observed that a once-daily topical application of this long-lasting antiseptic to the nares of either the infected virus-donor guinea pig or the susceptible virus-recipient guinea pig, or to the nares of both animals, prior to virus inoculation effectively reduced transmission of a highly transmissible influenza A virus, even when the donor and recipient guinea pigs shared the same cage. Daily treatment of the recipient guinea pig starting 1 day after initial exposure to an infected donor guinea pig in the same cage was similarly effective in preventing detectable influenza virus infection in the recipient animal.

We conclude that a daily application of this antiseptic formulation is efficacious in reducing the transmission of influenza A virus in the guinea pig model, and further study in this and other preclinical models is warranted.