Many countries are still heavily relying on rapid coronavirus tests at airports, events and schools, and yet negative test results currently aren’t a reliable way of ruling out an Omicron infection, according to new research. Many of the antigen tests available in Europe frequently fail to detect Omicron infections, researchers led by Munich virologist Oliver Keppler of Ludwig-Maximilians-Universität found in an analysis of nine commercially available rapid antigen tests. Eight of the tests detected Omicron infections more poorly than Delta infections, according to the study, which was publish…