Vinegar and its active component acetic acid inhibit SARS-CoV-2 infection in vitro and ex vivo

Interferon; ACE2: Angiotensin converting enzyme 2. Vero cells were seeded at 2.5×10 5 cell/well in 24-well plates in Eagle's minimum essential medium (EMEM) supplemented with 10% fetal calf serum (complete medium).Twenty-four h later, 50 plaque forming units (PFU) of a previously titrated SARS-CoV-2 isolate (GISAID accession ID: EPI_ISL_413489) were added to vinegar (from 0.28% to 0.008%) or acetic acid (from 0.1 to 0.5%) serially diluted (1:2) in PBS and incubated for 15 min at either 37°C or 45°C before addition to confluent Vero cells.