The Univ. of Nebraska Medical Center group has reported a research finding that bromelain extracted from pineapples (enzyme classified as a cysteine protease in proteolytic enzymes) is effective in suppressing infection with the new coronavirus (SARS-Co-2).
https://www.biorxiv.org/content/10.1101/2020.09.16.297366v1
Bromelain targets angiotensin-converting enzyme 2 (ACE2), type II membrane-penetrating serine protease (TMPRSS2) and SARS-CoV-2 S-protein, and thereby suppresses SAS-CoV-2 infection. Because bromelain is well absorbed through digestive organs and maintains its biochemical activity in the body, it is said that ingesting pineapples rich in bromelain will suppress infection with the new coronavirus (SARS-CoV-2).