-The Omicron variant of the coronavirus is on track to be the dominant strain of the virus in the United States, replacing the highly transmissible delta variant. -Omicron is more transmissible than delta, with a doubling time of about two days. -A new study showed that the Omicron variant multiplies 70 times faster in the human bronchial tubes than the initial COVID-19 infection or the delta variant. Omicron multiplies faster in airways, slower in lungs and therefore causes a less severe infection than delta. – It is still far too early, to make broad conclusions about Omicron’s severity, especially because hospitalizations and deaths typically lag several weeks behind infections. -This hyper-transmissible virus is coinciding with a time when many people are spending a lot of time indoors because of the winter and the holiday season. The delta and omicron variants along with the influenza virus are likely to lead to an inevitable surge in hospitalizations across much of the United States in the next few weeks. -With hospitalizations rising, sports leagues canceling games, colleges sending students home early and schools going back to virtual learning, Americans are starting to feel the unpleasantly familiar experiences of the pandemic all over again. -While recent studies show that the Omicron variant can partially escape immunity from vaccines and past infection, getting vaccinated and taking the boosters protects from severe infection. Unvaccinated individuals are at the highest risk of getting severe disease leading to hospitalization and death. -In addition to vaccines and boosters, masking, testing and taking precautions when gathering with others indoors help slow the spread. Author Mahesh S. Ochaney, MD