Danish authorities on Friday said they were investigating several cases of people found to have been infected with a mutated coronavirus transmitted from minks.
Virus mutations can occur when viruses jump from one specie to another, for example from mink to humans or back.
At least 214 people have been infected with a variant of the coronavirus that appeared in minks in June, said the Danish State Serum Institute (SSI).
The tally included 200 people in the west Danish region of North Jutland, which is home to most of the country’s 1,100 mink farms.
The SSI said five different groups of mink-related variants have been found in Denmark, with concerns mainly linked to the so-called cluster 5, which was found to weaken the ability to form antibodies and could make future vaccines ineffective.
So far 12 people were diagnosed with the strain from cluster 5, though they have not shown more severe symptoms than others.
Viruses from cluster 1 have not shown reduced susceptibility to antibodies, while results were pending for the other variants from the clusters 2-4, the SSI said.
Coronavirus was recorded in 216 Danish mink farms, prompting the government this week to order the cull of all farmed mink about 15 million animals – and a shutdown of the North Jutland region until early December, affecting about 280,000 people.