Winter of Omicron—The Evolving COVID-19 Pandemic

Omer et al asserts that nearly 2 years into the coronavirus pandemic, COVID-19 cases, hospitalizations, and deaths are rising in the US and in many other countries. Despite widespread availability of effective vaccines and novel therapeutics, health systems in many US regions are again being overwhelmed with largely unvaccinated or medically vulnerable patients filling emergency departments and intensive care units. Although most of these severe cases have been due to the Delta variant that has been dominant since May 2021,1 the recently identified Omicron variant is rapidly displacing Delta as the most common SARS-CoV-2 variant. The lack of universal uptake of COVID-19 vaccination and the emergence of the Omicron variant of SARS-CoV-2 are critical factors in the ongoing pandemic. In late November 2021 the identification of the Omicron variant of SARS-CoV-2 in South Africa and Botswana, quickly classified by the World Health Organization as a Variant of Concern, has again changed the trajectory of the pandemic.