In the first findings on how the Omicron variant (B11529) infects the respiratory tract, researchers from Hong Kong University (HKU) today reported that the virus multiplies 70 times faster in the bronchi than Delta and the original SARS-CoV-2 virus, which they said might explain why Omicron transmits faster.In other developments, countries such as the United Kingdom and South Korea—both reporting Delta (B1617.2) and Omicron community spread—reported record daily highs for COVID-19 cases.Lung replication isn't sole severity factorFor the respiratory tract study, HKU researchers used lung tissue samples to compare infection with the recent Omicron variant compared with Delta and the original virus from 2020.