Belgium reported the highest Covid mortality in Europe, in part because it always included both confirmed and probable cases. 66% of Belgian excess deaths occurred in nursing homes. Of these, only 27% were confirmed by a PCR test. It is quite possible that some of the non-confirmed nursing home deaths were not due to Covid, but due to the extreme circumstances.
(For instance, England and Wales saw 10,000 extra non-Covid dementia deaths in April. These are, essentially, deaths due to lockdown, panic and isolation.)
The Belgian Covid IFR in the general population is about 0.43%. Below 44 years it is 0.02%, from 45 to 64 it is 0.21%, reaching 2.6% at 85 years and 30% or more in nursing homes. National antibody seroprevalence is about 6%, though above 10% in Brussels. As usual, real coronavirus exposure might be higher (due to mild cases without IgG), and IFRs somewhat lower.
Even without age-adjustment, the number of excess deaths due to Covid in April 2020 in Belgium is comparable to the number of excess deaths in January 1951 and February 1960 due to strong seasonal influenza prior to vaccination campaigns.