March 22. A subvariant of Omicron, BA.2, is leading to a new wave of Covid-19 infections across Europe. Cases in the United Kingdom, Germany, the Netherlands and other countries are going up, driven by this very contagious coronavirus strain.
The proportion of Covid-19 cases due to BA.2 is rising in the United States, too. The US Centers for Disease Control and Prevention now estimates that 35% of new coronavirus cases are due to this subvariant. At the same time, restrictions are being lifted, and not a single US state requires mask mandates anymore (though masks are still required in some settings, including airports, public transportation, hospitals, nursing homes, and some schools and workplaces).