Antibodies testing - although useful to an extent, doesn’t identify people that have some previous immunity from other coronaviruses and T cell response is thought to be a possibly even more powerful response than your immune response, as these cells remember viruses and attack them, without your immune system.
More evidence does seem to be emerging on T cells being potentially the biggest weapon, I simply do not buy that in Stockholm only circa 10% of people are immune, just seems a totally unrealistic number to me.
https://www.dailymail.co.uk/news/article-8412807/Can-cold-coronavirus-immunity.html
This. It's getting really quite frustrating how many otherwise sensible, level-headed people are completely ignoring the emerging science on this.
Would also explain the now near-confirmed 70-80% asymptomatic rate - seen that percentage range now very consistently across many countries.