This is what the MIT Tech has to say about Sweden (and I agree): "Lessons from Sweden
Outside the US, researchers are also closely tracking the role of population immunity in national responses. Sweden, for example, did not impose a strict lockdown, and saw a large number of deaths starting in April. Since then, however, the number of new infections has declined. The nation’s leaders said last week that children would go back to school unmasked.
“I would say in Sweden there is no doubt that immunity plays an important role, more than in other countries,” says Britton. “Now this epidemic is slowly stopping.”
https://www.technologyreview.com/2020/08/11/1006366/immunity...