Nothing wrong with it - I just wish people would make relevant comparisons and the most relevant comparison is Sweden to Norway/Finland (similar population densities/cultures) and Sweden has done far, far worse, so holding Sweden up as some success story seems quite inappropriate to me. The fact that Sweden has a similar per capita death rate as ~5-10X more densely populated countries, like Italy, UK, France, Spain, etc., is another sign of how badly they did.
I was the first person on this board to bring up the intriguing possibility of T-cell cross-reactivity from prior exposure to other coronaviruses conferring some or even significant immunity to people who had never been exposed to SARS-CoV-2, so yeah, I know a little about it. The problem is scientists simply don't know if this cross-reactivity provides immunity or not for small or large numbers of people and are unlikely to ever know, since assessment of COVID infections for people with and without such T-cells, in large numbers would be the only way to know and I don't think there's any way that can be done with extremely-difficult-to-measure T-cells (but it would be a great study to do).
Also, given Sweden's/Stockholm's much lower level of people with antibodies (~6%/10% respectively, as per below), reflecting past COVID infection, vs. areas like NY/NYCMetro (13.4%/21.6%, respectively, with the Bronx up to 32%), London, Northern Italy, etc., I'd say it's highly unlikely that, even if there is some 20-40% magic cap on those infected due to cross-reactivity, Sweden would still be quite far from that, as opposed to NYC. And the fact that both (with close to 10MM people each) have in the range of 200-400 cases per day on a 7-day moving average tells me that their interventions are working (distancing in Sweden and masks/distancing in NYC with a far higher density), but that the virus is nowhere near under control.
I'm praying for cross-reactivity to be real and to equate to some cap on how many can become infected, which could lead to herd immunity levels being much lower than currently thought (55-80% range), but in the absence of compelling data to that effect, I think our focus should be on: a) reducing transmissions, cases, hospitalizations and deaths by masking/distancing with testing/tracing/isolating to prevent small flare-ups from becoming major outbreaks and b) continuing our extraordinary scientific efforts to find working treatments/cures and on developing and distributing vaccines (also vaccines should improve everyone's immunity, even those with cross-reactive T-cells).
