https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103721/
Garlic: a review of potential therapeutic effects
Antiviral properties
In comparison with the antibacterial action of garlic, very little work has been done to investigate its antiviral properties. The few studies have reported that garlic extract showed in vitro activity against influenza A and B (Fenwick and Hanley, 1985 ▶), cytomegalovirus (Meng et al., 1993 ▶; Nai-Lan et al., 1993 ▶), rhinovirus, HIV, herpes simplex virus 1 (Tsai et al., 1985 ▶), herpes simplex virus 2 (Weber et al., 1992 ▶), viral pneumonia, and rotavirus. Allicin, diallyl trisulfide and ajoene have all been shown to be active (Hughes et al., 1989 ▶; Weber., 1992 ▶).