New Mutated Virus?
According to a leading Dutch expert, the mutated virus, which appears to have spread from animals to humans in Denmark, has been detected retrospectively at a mink farm in the Netherlands. The mink were culled, and the mutated strain did not infect humans. Six countries have reported coronavirus outbreaks at mink farms. They include the Netherlands, Denmark, Spain, Sweden, Italy and the US. Mink are known to be susceptible to Sars-CoV-2, the virus that causes Covid-19, which can spread rapidly from animal to animal in conditions where thousands of animals are kept nearby.
The farmed weasel-like animals have become infected by farm workers during the pandemic and have occasionally passed the virus on to humans, raising the virus's risk of acquiring mutations. Danish scientists are worried that genetic changes in a mink-related form of the virus, infecting a dozen people, can make future vaccines less effective. The genetic change is in the spike protein of the virus, which is essential in the body's immune response and a key target for vaccines. The Danish genome sequences were recently released on a public database, allowing scientists in other countries to search for evidence of the mutation.
A veterinary professor expert at Wageningen University said analysis of genetic data from the Netherlands revealed one previous case of the mutation at a mink farm in early May. We have once seen a mutant virus with a comparable mutation in the spike protein-encoding region, in mink in the Netherlands, but this mutant did not spread to humans, and the mink of the involved farm were culled." The Netherlands launched a widespread cull of mink after signs that humans had picked up coronavirus from mink in a small number of cases. The genetic data from Denmark was released on an international database a few days ago, with some scientists questioning why it had not been released sooner.
I think that it is most disappointing that the data has only just reached the light. The genetic changes needed careful evaluation, as reports from WHO suggested an effect on immunity. This may be what triggered the enhanced quarantine measures for travellers from Denmark. Nevertheless, far more careful evaluation is urgently needed.
Mink farming required "enhanced biosecurity or suspension at this time" It is usual for viruses to change over time and accumulate mutations. However, experts are particularly concerned when viruses pass between humans and animals. Several animals have caught the virus from humans, but mink appear particularly susceptible. While mutations in viruses happen as they spread, the question is whether these change the characteristics of the virus. "At this stage, it seems that there may be issues with vaccine effectiveness, but this is still unclear," he said. Effective surveillance is needed to detect the emergence of new pathogens early and then have an effective way of responding, he added.
The European Centre for Disease Prevention and Control, an agency of the European Union, has said it will publish risk assessments on the spread of Sars-CoV-2 in mink farms this week. It remains to be seen if the Danish mutation in the Sars-CoV-2 virus will be detected in mink farms in other countries. The outbreak of this mutated variant has become known as "cluster 5".
In Sweden, there have been outbreaks at mink farms in the south-east part of the country. Scientists reported that the genetic mutation found in Danish mink had not been detected so far.