Denmark says it plans to destroy its whole population of minks after the animals apparently spread the new coronavirus to humans. Prime Minister Mette Frederiksen said government investigators had discovered a mutation in the virus in 12 people in northern Denmark. The individuals are believed to have been infected by minks. Denmark’s health minister said that half of nearly 800 human COVID-19 cases in northern Denmark “are related” to minks. Denmark is the world’s main exporter of mink fur. Most of the fur is sent to China and Hong Kong. Frederiksen called the situation “very serious” and warned that the mutation could make future coronavirus vaccines ineffective. Health officials said they found virus versions in humans and minks that showed decreased sensitivity to antibodies. They said this could make future vaccines less effective.