A new study investigates the antiviral activity of four plant extracts. Among the plants studied are: green tea (Camellia sinensis), pomegranate juice (Punica granatum), black choke berry juice (Aronia melanocarpa), and elderberry syrup (Sambucus nigra). These medicinal plant extracts were effective in vitro for stopping viral attachment, reducing viral load, and stopping the spread of infectious SARS-CoV-2, influenza, and adenovirus.