COVID-19 ISO Insights

WHO: Mink-related 'Cluster 5 Variant' of SARS-CoV-2 Raises Concern

November 23, 2020

By: Christopher Sirota, CPCU

Many viruses naturally mutate, especially RNA viruses such as HIV, influenza, and SARS-CoV-2, and usually these mutations do not affect viral transmissibility or the severity of a resulting disease, according to an article in Nature.

However, sometimes a mutation makes experts stop and take notice.

Such is what reportedly happened in Denmark regarding the transmission of the SARS-CoV-2 virus from humans to farmed minks, and back to humans again.

According to a release from the World Health Organization (WHO), experts in Denmark alerted the world about a variant of the SARS-CoV-2, now called "cluster 5," which seems to contain mutations not identified before. The variant was reportedly confirmed in the farmed minks and in twelve COVID-19 patients. The experts are reportedly concerned about these mutations, in part, because their preliminary findings indicate a "moderately decreased sensitivity to neutralizing antibodies" which could have implications on vaccines being developed.

A related New York Times article explains Danish health authorities are concerned, in part, because:

One of the mutations occurs on a part of the virus — the spike protein — that is targeted by many potential vaccines. In lab studies, cells with this variant of the virus were exposed to antibodies, which did not act as strongly as they had with other coronavirus variants.

[However], [t]he reaction to antibodies in laboratory cells does not necessarily indicate that the mutated virus would be resistant to vaccines; it merely raises that possibility.

Other animals have reportedly contracted COVID-19 from humans, such as domestic dogs, cats, lions, and tigers. However, per the Times, so far, minks are the only animal to become infected from humans and then transmit it back to humans.

The WHO explains that:

As viruses move between human and animal populations, genetic modifications in the virus can occur. These changes can be identified through whole genome sequencing, and when found, experiments can study the possible implications of these changes on the disease in humans.

Per the WHO, Denmark has taken or has planned the following actions as a precaution:

  • "Culling of all farmed mink (more than 17 million) in Denmark, including its breeding stock;
  • Enhancing surveillance of the local population to detect all COVID-19 cases, including through population-wide mass PCR testing for the region of North Jutland;
  • Expanding the percentage of sequencing of human and mink SARS-CoV-2 infections in Denmark;
  • Rapid sharing of the full genome sequences of the mink-variant SARS-CoV-2; and
  • Introducing new movement restrictions and other public health measures to affected areas in North Jutland to reduce further transmission, including movement restrictions between municipalities."

Notably, also per the WHO, the following additional countries have reported SARS-COV-2 in farmed mink: the U.S, the Netherlands, Sweden, Spain and Italy.