It is possible that there is some pre-existing immunity to SARS-Cov-2, making herd immunity closer | Nature User aledomyy, in the Novel Coronavirus (COVID-19) subreddit, 10 Aug 2020
Pre-existing immunity to SARS-CoV-2: the knowns and unknowns User traversecity, in the Novel Coronavirus (COVID-19) subreddit, 03 Aug 2020
Pre-existing immunity to SARS-CoV-2: the knowns and unknowns User BurrShotFirst1804, in the Novel Coronavirus (COVID-19) subreddit, 16 Jul 2020
Pre-existing immunity to SARS-CoV-2: the knowns and unknowns User FredoSosa, in the Novel Coronavirus (COVID-19) subreddit, 15 Jul 2020
La Jolla Institute of Immunology: T-cell reactivity against SARS-CoV-2 found in 20-50% of blood samples collected from people previously unexposed to COVID-19. Possibly stemming from exposure to a previous common cold coronavirus User antiacela, in the Conservative subreddit, 15 Jul 2020
La Jolla Institute of Immunology: T-cell reactivity against SARS-CoV-2 found in 20-50% of blood samples collected from people previously unexposed to COVID-19. Possibly stemming from exposure to a previous common cold coronavirus User bomb-bomb, in the LockdownSkepticism subreddit, 14 Jul 2020
Pre-existing immunity to SARS-CoV-2: the knowns and unknowns User GallantIce, in the COVID-19 subreddit, 08 Jul 2020