One also have to account for T-cell immunity which is double that of normal anti body immunity. 14.5 percent of Sweden capital Stockholm population had antibodies according to COVID-19 test lab Werlabs. If you take 14.5 + 2x14.5 you get 43.5 percent that have immune system protection from COVID-19 in Stockholm. 43.5 percent is close to when we get herd immunity. In smaller cities in Sweden there is not the same population immunity so it may still spread there up to the herd immunity point. People still can get infected by a spreader if about 43.5 percent have immune system response.

Werlabs anti body measures of Stockholm news https://www.mynewsdesk.com/se/werlabs/pressreleases/nivaan-a...

Herd immunity possible at above 40 percent https://www.svd.se/ny-berakning-stockholm-kan-na-immunitet-i...

T-cell response https://svt.se/nyheter/inrikes/immunitet-mot-corona-storre-a...