The World Health Organization is looking at biosecurity around mink farms in countries across the world to prevent further "spillover events" after Denmark ordered a national mink cull due to an outbreak of coronavirus infections in the animals.Maria van Kerkhove, the WHO's technical lead for Covid-19, told a briefing in Geneva on Friday that transmission of the virus between animals and humans was "a concern", but added:
"Mutations (in viruses) are normal. These type of changes in the virus are something we have been tracking since the beginning."
The risk was much lower in animals other than mink, a second WHO expert said.
"We are working with regional offices ... where there are mink farms, and looking at biosecurity and to prevent spillover events," van Kerkhove said.
Denmark said earlier this week that it plans to cull its entire mink population and announced strict new lockdown measures in the north of the country to prevent a mutated coronavirus from spreading in the animals and to humans.
It has raised concerns that the mutations could affect the potential efficacy of Covid-19 vaccines in development.
Soumya Swaminathan, the WHO's chief scientist, said on Friday, however, that it is too early to jump to conclusions about the implications of mutations in the virus found in mink.
"We need to wait and see what the implications are but I don't think we should come to any conclusions about whether this particular mutation is going to impact vaccine efficacy," she said. "We don't have any evidence at the moment that it would."
Denmark's State Serum Institute, which deals with infectious diseases, said a mutated strain of the SARS-CoV-2 coronavirus has been found in 12 people and on 5 mink farms.
Kerkhove said Denmark's decision to cull its mink was aimed at preventing the establishment of "a new animal reservoir for this virus".
Mike Ryan, the WHO's top emergencies expert, said other farm animals, such as pigs and poultry, had "very strict" biosecurity in place to prevent viruses jumping the species barrier.