As the omicron variant gains momentum in Europe and the United States, scientists are rewriting their expectations for the COVID-19 pandemic next year.

Just weeks ago, disease experts were predicting that countries would begin to emerge from the pandemic in 2022 after enduring a series of surges driven by the alpha, beta, gamma and delta variants. First among them would be populations with a significant amount of exposure to the coronavirus, through a combination of infections and vaccination.

In those places, COVID-19 was expected to ease into an endemic disease, hopefully with less-severe periodic or seasonal outbreaks. Vaccines, available for much of 2021 only in wealthy nations, could reach the majority of the global population by the end of the year ahead.