Since February 2020, it had been known that the SARS-CoV-2 virus that causes Covid-19 in susceptible individuals, was very closely related to other coronaviruses, some widely circulating. The likelihood that immune systems would find it completely novel was low.
— Read on citizen.co.za/news/opinion/opinion-columns/2443650/lockdowns-dont-save-lives-and-sweden-is-all-the-proof-you-need/amp/