Bee propolis has been investigated for its antiviral properties, including activity against influenza viruses. Several in vitro and animal studies have shown that compounds found in bee propolis, such as flavonoids and phenolic acids, can inhibit the replication of influenza A virus and reduce viral load. For example, research published in Phytotherapy Research (2011) and Antiviral Chemistry & Chemotherapy (2017) demonstrated that extracts of propolis were able to reduce influenza virus infectivity in cell cultures and animal models, possibly by interfering with the viral envelope and inhibiting viral entry into host cells.

Despite these promising preclinical results, clinical evidence in humans is limited. A few small human studies and anecdotal reports suggest that propolis may help reduce the duration or severity of upper respiratory infections, but well-powered, placebo-controlled studies specifically examining its efficacy against influenza in humans are lacking. As a result, while there is some scientific rationale and early-stage evidence for the use of bee propolis against influenza, its effectiveness has not been conclusively demonstrated in clinical settings, and its use is not recommended as a substitute for influenza vaccination or antiviral medications.

In summary, bee propolis shows potential as an adjunctive natural remedy against influenza based on laboratory research, but robust clinical trials are needed to confirm its benefit in humans.