> Masks are common in the supermarkets, etc.

Not sure where you got this information - masks are not commonly worn at all in Sweden. I see perhaps 1 mask per week, unless I go into the city center, then I might see 10 in a day.

The Swedish public health authorities are not currently recommending general usage of face masks, citing mainly the lack of evidence of the effectiveness of general mask usage (wearing a mask can cause you to get lulled into a false sense of security, for example).

See https://www.folkhalsomyndigheten.se/smittskydd-beredskap/utb...

(in Swedish, unfortunately)