Cluster 5 is a designation used by the Danish Statens Serum Institut for a virus variant described by the institute in autumn 2020, in connection with investigations of SARS-CoV-2 infection among mink and humans in the north of Jutland, Denmark.[1]
On 3 November 2020, the institute delivered a risk assessment, in which a preliminary experiment with this virus variant described on one and a half pages,[2] was the basis for an assessment concerning the efficacy of future COVID-19 vaccines.[3] With reference to this risk assessment, the Danish government on 4 November 2020 mandated the killing all the country's mink.[4] and a lockdown with tightened restrictions was introduced in seven North Jutland municipalities.
At the time the decision to kill all Danish mink was made, the virus variant had last been detected on 15 September 2020.[5][6] After subsequent testing and sequencing of positive samples in the seven North Jutland municipalities, the date of the latest finding was still 15 September 2020.[7]
The World Health Organization wrote on 6 November 2020 with reference to the preliminary experiment, that "Further scientific and laboratory-based studies are required to verify preliminary findings reported and to understand any potential implications of this finding in terms of diagnostics, therapeutics and vaccines in development."[8]
The Danish Medicines Agency was asked for its assessment of the virus variant, the day after the government had decided to kill all the country's mink.[9] The agency concludes in its assessment that the mutations that characterize the virus variant are not likely to have substantial impact on the efficacy of first-generation vaccines.[10]