Enlarge / Members of the public queue outside a pharmacy to receive COVID-19 antigen tests in Paris on January 6, 2022. Omicron subvariants BA.4 and BA.5 are on the rise in the European Union, spurring officials there to warn that a surge of COVID-19 cases will likely follow in the coming weeks. In an alert Monday, the European Center for Disease Prevention and Control cautioned that various facto