Is a dangerous new coronavirus strain circulating in farmed mink?
The Danish government has ordered the slaughter of all farmed mink in the country after the reported discovery of a mutant form of coronavirus in the animals. It has already spread to humans.
What do we know about the situation in Denmark?
According to a report in the Danish newspaper Berlingske, 207 mink farms have seen infections of coronavirus. The authorities have failed to contain the virus, and all 17 million farmed mink in Denmark will now be culled, said Denmark’s prime minister Mette Frederiksen at a press briefing on 5 November. Denmark has the world’s largest mink industry.
The Danish prime minister described the mutated virus as “a serious risk to public health and to the development of a vaccine”. However, health minister Magnus Heunicke told the press briefing that there is no sign yet that the mutant virus causes more serious symptoms of covid-19.
Some areas of northern Jutland – the region of Denmark that connects to the European mainland – will be isolated to stop the spread of the virus in humans. Frederiksen said a “mutant” virus has been identified in five farms and 12 people have become infected with it.
What sort of mutant?
The State Serum Institute issued a statement (in Danish) confirming that multiple mutant viruses have been isolated from mink, and that seven of these have mutations in the spike protein, which the virus uses to enter cells and which is important to the immune response and a key target for vaccines.
One of these viruses has four mutations in its spike protein, and in laboratory tests has been found to be more weakly inhibited by antibodies from humans who have been infected with the coronavirus. This could in theory make a vaccine less effective. But the virus itself in not more dangerous or contagious. According to a Google translation, the statement concludes that “as a citizen, you do not have to worry”.
Can mink really catch the coronavirus?
Yes. There are already scientific reports of farmed mink in the Netherlands catching it from humans. And in June, more than 90,000 mink were culled in Aragon, Spain, after the virus was detected in fur farms.
Can mink pass it to humans?
Yes. One of those reports from the Netherlands says that at least one worker on a mink farm caught the virus from the animals. The worker showed only mild respiratory disease.
Read more: Your covid-19 risk: How to navigate this new world of uncertainty
What do scientists say?
Francois Balloux, a professor of genetics at University College London (UCL), took to Twitter to describe the report as “highly problematic”. He said his colleague Lucy van Dorp at UCL has already documented numerous coronavirus mutants arising repeatedly in mink, none of which are concerning for humans. The claim that this mutant may be resistant to a vaccine is “idiotic”, he said. Such mutations might emerge in humans once we have a vaccine but won’t appear in mink, he said.
Other scientists echoed his views. James Wood at the University of Cambridge said he understands that the mutation is on the spike protein, which the virus uses to enter cells and which induces an antibody response. However, “the true implication of the changes in the spike protein have not yet been evaluated by the international scientific community and are thus unclear. It is too early to say that the change will cause either vaccines or immunity to fail,” he said in a statement.
Virologist Ian Jones at the University of Reading in the UK said that it wasn’t surprising that the virus had mutated, as it would need to adapt to mink. Denmark’s precautionary action would make it less likely that the new virus would spread widely in humans, he said in a statement.
Is the virus likely to spread to other animals?
Yes, very. More than 60 mammal species are known to be definitely or probably susceptible, ranging from gorillas and chimps to foxes, yaks, giant pandas and koalas. Even some whales, dolphins and seals may be able to catch it.
Why did nobody see this coming?
We did. Even before this happened, virologists were concerned about “reverse spillover”, which is when humans pass the virus on to domestic or wild animals. That could be a problem for the animals as some species fall ill and die. It could also spell trouble for us, as animals could become a new reservoir of virus and make the pandemic even harder to control. Animals could also be a crucible for the virus to mutate into another novel coronavirus.
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The Danish government has ordered the slaughter of all farmed mink in the country after the reported discovery of a mutant form of coronavirus in the animals. It has already spread to humans
COVID-19 Expert Database
What do we know about the new strain of this virus that is more infectious than the first strains?
What our experts say
Studies claim that newer strains of the COVID-19 virus in Europe and the United States spread more rapidly and are more infectious than the original strain of the virus, which was first discovered in Asia in early 2020.
A new strain, known as the ‘G614 variant’ or the ‘D614G spike mutation’, has been found in many countries. So far research shows that the new strain of coronavirus does not change the severity of symptoms. The public should continue to take the same recommended preventative measures of wearing a face covering, maintaining 6 feet physical distance and washing their hands with soap and warm water.
Viruses constantly change as they reproduce in order to keep spreading into more cells. These changes are called “mutations,” and though most mutations are not helpful to the virus, the mutations that help the virus reproduce contribute to the virus spreading. Mutations create a new, updated version of the virus, which we call a “strain.”
In the case of COVID-19, the ‘D614G spike mutation’ is currently the most common. It impacts something called the “spike proteins” of the virus, which are the spiky parts on the outside of all coronaviruses that help them get into the body of a person and infect more cells. The strain has more spike proteins, which means the virus is less likely to break off when it is trying to invade the human body, making it more likely to infect the exposed individual. With this change, some researchers believe the current strain of the virus is roughly 10 times more infectious than the earliest versions studied in laboratories.
It’s important to note that these recent studies show that while it is easier for the new strain of the virus to infect people, it does not make the infections any worse or better than other strains of COVID-19. Even if you are more likely to get sick from the virus due to the G614 mutation, your chances of having severe symptoms are the same as they have always been.
This entry was updated with new information on August 25, 2020
Context and background
Studies and news articles are circulating about a potential new strain of the novel coronavirus SARS-CoV-2. Viruses mutate (or change) as part of their life cycle. Some of these changes have more impact on humans than others.
RNA viruses, such as influenza and measles tend to be more prone to mutations, compared to DNA viruses, such as herpes and human papillomavirus. Coronaviruses are RNA viruses that generally have been found to mutate slower than influenza. Some forms of SARS-CoV-2 have mutated and now look different than the original version of it found in China. More research is needed to understand the implications of any mutations in SARS-CoV-2.
This entry was updated with new information on August 25, 2020
Studies claim that newer strains of the COVID-19 virus in Europe and the United States spread more rapidly and are more infectious than the original strain of the virus, which