A new coronavirus mutation that began in Denmark’s mink population has spread beyond the first discovered areas of the country. More than 200 people have been infected with the mink-related coronavirus.
Scientists suspect that the virus spreads in mink farms through infectious droplets, dust containing feces, feed, or bedding.
In addition to this, six countries have reported coronavirus outbreaks at mink farms. They include the Netherlands, Spain, Denmark, Italy, Sweden, and the US.
Minks, like their close relatives, ferrets, are also susceptible to coronavirus. Like humans, they may show a range of symptoms, from no signs of disease at all to serious problems such as pneumonia.
The mink has caught the virus from humans, but genetic detective work has shown that in a few cases, the virus seems to have passed another route, and the virus has spread back to humans from the mink.
The mutation of the coronavirus has triggered culls of all 17 million mink in Denmark
According to a leading Dutch expert, the mutant virus appears to have spread from animals to humans in Denmark and has been retrospectively detected in a mink farm in the Netherlands.
Danish authorities have imposed a lockdown on parts of the country after finding genetic changes that may undermine the effectiveness of the Covid-19 vaccine in the future.
He said the minks were culled and the mutation did not infect humans there.
Large numbers of minks kept in mink farms have been infected with the virus from infected workers. Moreover, in a few cases, the virus has spilled back to humans from mink skins and has absorbed genetic changes during transmission.
Danish scientists believe that such mutations are worrisome and concerning because they have the potential to reduce vaccine efficacy. Fearing that more than a dozen people will be infected, the government has ordered the killing of all farmed mink.
If the mutation is triggered by a specific protein currently targeted by vaccine developers, which triggers an immune response in humans, then this means that if this new virus strain emerges from the mink, even if it is vaccinated, humans will start to spread it, and the vaccine will not be able to protect it, Dr. Peyre said.
Genetic changes are part of the Sars-CoV-2 virus. It is called the spike protein. This protein is essential for immunity and is the target of certain future vaccines and treatments.
Professor Joanne Santini of University College London said that the mink has become a reservoir of the virus, and other wild animals and domestic animals that may be susceptible also need to be monitored.
The Danish genome sequence was recently released on a public database, allowing scientists in other countries to look for evidence of the mutation.
Professor Wim van der Poel, a veterinary expert at Wageningen University, said that an analysis of Dutch genetic data revealed a previous case of mutation in the mink farm.
He stated: Among the mink in the Netherlands, we have seen a mutant virus with comparable mutations in the spike protein-encoding, but this mutant virus has not been transmitted to humans, and the minks in the related farms have been culled.
Dutch launched a widespread cull of mink after signs, in a few cases, that humans had picked up coronavirus from mink.
A few days ago, the Danish genetic data was released on an international database, and some scientists questioned why it was not released earlier.
I think the most disappointing thing is that the data is just a fledgling,” said Professor James Wood, head of the Department of Veterinary Medicine at the University of Cambridge, UK.
He said that genetic changes need to be carefully evaluated because the Danish report shows an impact on immunity. This may have triggered the tightening of quarantine measures for travelers from Denmark. But a more careful assessment is urgently needed.
He added that mink farming needs to enhance biological safety (or suspension) at this time.
It is normal for the virus to change over time and accumulate mutations, but experts are especially concerned when the virus spreads between humans and animals.
Professor Dirk Pfeiffer of the Royal Veterinary College in London said that although the mutation of the virus has been occurring during the spread, the question is whether these mutations will change the characteristics of the virus.
He stated: At this stage, it seems that there may be a problem with the effectiveness of the vaccine, but this is unclear.
He added that effective surveillance and early detection of new pathogens are required, and then effective countermeasures are taken.
The European Center for Disease Control and Prevention, an EU agency, stated that it will release a risk assessment on the spread of Sars-CoV-2 in mink farms this week.
Whether the Danish mutation of the Sars-CoV-2 virus (causing Covid-19) has been detected in other countries with mink farms remains to be seen. The outbreak of this mutant variant has been referred to as ‘Cluster 5’.
In Sweden, an outbreak has occurred at mink farms in the southeast of the country. Scientists reported that no genetic mutations found in Danish mink have been found so far.
Genetic Research on Strains
Scientists in Denmark are conducting genetic research on strains related to mink and have been shared genetic data with other researchers for further research.
We need to find out where these mutations are, we need to look at the impact on the spread of the virus and how infectious it is, because if it is changing and is more infectious or has a wider host range, then it’s really scary but it may be not because we don’t know, Professor Santini said.
Some scientists have called for new restrictions on mink production, saying that mink farming “has hindered our response and recovery to the pandemic.
Three scientists from Denmark, China, and Malaysia wrote in a recent letter to the journal Science that there is an urgent need to monitor, restrict, and where possible ban mink production.
WHO also calls on all countries to strengthen the monitoring of mink farms and strengthen biosecurity measures.
If countries cannot take the right steps at the right time, the future will be dark.