Denmark is set to cull its entire population of captive minks in an attempt to stop the spread of Covid-19 after scientists identified a dozen people who have been infected with a mutated variant of the virus found in mink. It's thought that totals between 15 million and 17 million animals.
The Danish government announced the mink cull on November 4 saying it was based on a new risk assessment by the Danish scientific authorities (Statens Serum Institut), which found at least 12 people in the country have been infected with a mutated variant of SARS-Cov-2 that’s been found in five mink fur farms in the north of the country.
However, there is currently little scientific evidence publicly available on this specific variant, so some scientists have called for caution when reading sensational headlines about the situation in Denmark.
SARS-Cov-2, the coronavirus that causes Covid-19, has been detected in over 200 mink farms across mainland Denmark. The US has also confirmed cases of both minks and humans contracting Covid-19 at fur farms. Minks, like many other species of animals, are susceptible to being infected with Covid-19. Due to the cramped conditions of the fur farms, it’s very easy for the virus to race through the mink population once it has entered. It’s also been apparent for some time that SARS-CoV-2 can be transmitted from mink to human, with hundreds of human cases in Denmark thought to be linked to the animals
The Danish authorities have additionally suggested that the newly identified mutation might affect the effectiveness of a future vaccine, although this claim should be treated with a pinch of salt until further evidence is available.
“The Danish health authorities, Statens Serum Institut, have found a mutation and preliminary studies suggest that this mutation may affect the effectiveness of the current candidate for a vaccine against Covid-19,” Magnus Heunicke, the Danish Minister for Health, said in a statement.
“However, there is no evidence that those people infected with this mutation experience a more serious disease. A large virus reservoir of mink increases the risk of mutations re-emerging, which increases the risk that vaccines will not provide optimal protection."
On the other hand, some experts have dismissed this concern. Firstly, countless mutations are constantly occurring in SARS-CoV-2, most of which have little real consequence, and there are many known variants of the virus. Further to that point, there is no evidence yet to suggest that this newly identified variant is any more deadly, dangerous, or transmissible to the ones currently circulating through the world’s population.
“SARS-CoV-2 mutations acquired in minks are not concerning. We already knew that SARS-CoV-2 can transmit from minks to humans… This should be of no concern in terms of the evolution of the transmissibility of the virus,” tweeted Professor Francois Balloux, director of University College London's Genetics Institute.
Addressing the suggestion a mutation might affect a future vaccine, he added: “The 'vaccine escape' scare story is just idiotic. Vaccine-escape mutations may (or not) arise in humans in the future, if they are advantageous to the virus (once vaccines will be deployed). They definitely won't be fuelled by mutations having emerged in minks.”