On Sept. 1, 2020, scientists at deCODE genetics in Iceland, a subsidiary of Amgen, published a study in The New England Journal of Medicine, that showed that antiviral antibodies against SARS-CoV2 do not decline within four months of diagnosis.

The aim of the study was to obtain understanding of the nature and durability of the humoral immune response to infection by SARS-CoV-2, the virus that causes COVID-19.

To that end the scientists measured antibodies in the sera of 30,576 persons in Iceland (8.4% of the nation) using six assays (two of them pan-Ig) and determined that the best measure of seropositivity was a positive result with both pan-Ig assays. They tested 2.102 samples from 1,237 qPCR-positive persons obtained up to 4 months from diagnosis. They also measured antibodies in 4,222 samples from exposed, quarantined persons and 19000 persons not known to have been exposed.COVID-19.

Of quarantined persons, 2.3% were seropositive and of those with unknown exposure, 0.3% were positive.

The scientists estimated that 0.9% of Icelanders were infected by SARS-CoV-2 and 44% of people infected with SARS-CoV2 in Iceland were not diagnosed with qPCR. The infection fatality rate is 0.3%. Of the 1,797 persons who recovered from SARS-CoV-2 in Iceland, 1,107 (91.1%) were seropositive.