A recent study by a group of Chemical and Biomolecular Engineering researchers from the University of Sydney’s Faculty of Engineering in Journal of Functional Foods showed that compounds from elderberries can directly inhibit the influenza virus’s entry and replication in human cells, and can help strengthen a person’s immune response to the virus. The group performed a comprehensive examination of the mechanism by which phytochemicals from elderberries combat influenza infections.  What the study has shown us that the common elderberry has a potent direct antiviral effect against the flu virus,” said Dr. Golnoosh Torabian, chief researcher.  “It inhibits the early stages of infection by blocking key viral proteins responsible for both the viral attachment and entry into the host cells.” 

The researchers used commercially farmed elderberries, which were turned into a juice serum and were applied to cells before, during, and after they had been infected with the influenza virus. The phytochemicals from the elderberry juice were shown to be effective at stopping the virus infecting the cells, however to the surprise of the researchers; they were even more effective at inhibiting viral propagation at later stages of the influenza cycle when the cells had already been infected with the virus. 

Golnoosh Torabian, Peter Valtchev, Qayyum Adil, Fariba Dehghani. Anti-influenza activity of elderberry (Sambucus nigra). Journal of Functional Foods, 2019; 54: 353 DOI: 10.1016/j.jff.2019.01.031 

Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. J Int Med Res. 2004 Mar-Apr;32(2):132-40.