Just to put in perspective how critically important @Mesoy640 's seroprevalence data is:
Denmark, 2.7% seropositive for COVID19
Recognized cases = 4830.
Population = 5.6 million.
Crudely (this is all aggregate) 2.7% seroprev would imply 151,200 cases in a country that size.

That means:
1. They are missing 93% of infections despite an excellent PH system.
2. They are much further into this epidemic than one would have expected.
3. The infection fatality ratio for DM = 0.1%, as compared to 3.7% CFR.

0.1% IFR is a big deal. It is 10x that of 2009 H1N1, and the attack rate here is higher because part of the pop had immunity to H1N1 (those born pre-1957).

The fact that those born pre-1957 were largely immune to H1N1 (older folks who DID get it were more likely to die)

was the reason that pandemic was less impactful.

We don't have that luxury this time around, as demonstrated by the terrible toll this is taking in older individuals.