Since early this month, reports on the decision of Denmark health officials to eliminate or kill millions of minks in over 1,000 farms because of COVID-19 issues have illuminated boiling apprehensions among experts about the susceptibility of the said animals to the pandemic virus, not to mention what animal contagions might affect humans.
Then, later last week, health officials here release genetic and investigational data on a cluster of the new coronavirus, SARS-CoV-2 mutations circulating in farmed mink, as well as in people, several days after the announcement on mutations that could reportedly jeopardize the efficacy of potential vaccines for COVID-19.
Reports on mutations urged the Danish Prime Minister Mette Frederiksen to announce earlier this month the government’s plan to “end mink farming for the foreseeable future” and discard about 17 million animals, igniting a fierce argument on whether such initiative was legal.
However, researchers were cautious not to raise a fear until they saw the data. Now, scientists who have analyzed the data specified, the mutations themselves are not particularly alarming since there is little evidence that they enable the virus to transmit more easily among humans, make it more fatal, or will endanger treatments and vaccines.
(Photo : Ritzau Scanpix/Mads Claus Rasmussen via REUTERS)
A man handles culled mink at the farm of Henrik Nordgaard Hansen and Ann-Mona Kulsoe Larsen near Naestved, Denmark.
University of Oxford virologist Astrid Iversen said the mink-associated mutations “we know of are not associated” with swift spread, nor with any changes in both disease and death.
Nevertheless, scientists claimed, discarding the animals is possibly essential, given the rapid and uncontrolled transmission of the virus in mink, identified in moreover 200 farms since June, making the animals a “massive viral” that can easily infect humans.
In regions that have affected mink farms, many people with COVID-19 increase considerably, explained Iversen. In addition, there are approximately three times more mink compared to people in Denmark. That’s what makes mink-culling essential.
Meanwhile, Statens Serum Institut virologist Jannik Fonager said, uncontrolled spread in mink increases the opportunity as well to progress and develop mutations that could be worrying. Copenhagen-based Statens Serum Institut is the health authority in Denmark, leading the investigations.
Fonager added, researchers shared their concerns with the government, but the latter indeed decided to cull the mink.
The government, on November 10, submitted legislation to authorize the cull and has urge farmers to start the culling process.
Mutations in Minks
Reports on the data said, according to Fonager, scientists in Denmark “have sequenced viral samples from 40 mink farms” and found around 170 coronavirus variants.
He also said, the viral samples from humans, signifying about a-fifth of Denmark’s COVID-19 confirmed cases, the scientists reportedly found about 300 variants in humans “that can be traced to minks.” Meaning, the variants contain mutations believed to have originally occurred in mink. Such discovery, Fonager elaborated, is something they “really want to keep a close eye on.”
In viral samples collected from mink and people, study authors have detected several mutations in the gene encoding the spike protein of the coronavirus, which it uses to go into the cells.
The detection concerns scientists as changes in this region could impact the ability of the immune system to identify infection. Relatively, a lot of vaccines train the immune system as well to block the spike protein.
Of specific concern is a viral variant that contains a unique combination of mutations, also known as “Cluster-5,” which was detected in five farms and 12 people in the North Jutland region.
According to Fonager, the said variant causes three changes in amino acid and two removals in the spike protein. Nevertheless, scientists who have investigated the available data said such claims are hypothetical.
Iversen added, the Cluster-5 variant appears to be a “dead end” in humans as it has not spread widely. Furthermore, a lot of those who were infected were working on the farms and were, perhaps, exposed to high viral doses.
The said variant, Iversen elaborated, has not been seen since September despite wide-ranging sequencing and data sharing.
The expert also said the investigational study is very limited to draw a conclusion about its effects for vaccines and therapies.
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