Back in December, omicron BA.1 caused a massive surge in cases in Denmark, similar to the surge in the United States. But then, just as cases began to decline, BA.2 started spreading very rapidly in Denmark. After only a few weeks, BA.2 took over the outbreak there and has lengthened Denmark's surge. Denmark's cases are climbing steeply, with more than 40,000 recorded each day. Since the second week in January, BA.2 has caused more than 50% of those cases,
according to the Statens Serum Institut in Copenhagen.