A new study published in Cell on May 14 shows that people, who had never been exposed to COVID19, had immune T cells that could recognize & fight the virus:
https://sciencenews.org/article/coronavirus-covid-19-t-cells-patients-immune-system
This suggests that we as a society already have certain immunity to COVID19.
No need for vaccine!
https://twitter.com/NikolovScience/status/1266059311664390144