There may never be "herd immunity" if the virus immunity quickly wanes as the latest research is finding.
So no vaccine ever.
Just like the common cold another corona virus that effect humans.
https://www.businessinsider.com/coro...s-covid-2020-4
""Scientists fear that it may prove impossible to produce a working coronavirus vaccine and believe the world may have to simply learn to adapt to the permanent threat of COVID-19.""
https://www.news.com.au/lifestyle/he...3cc64ab2943608
“There is no vaccine against the common cold.”