This Week in COVID-19: As Omicron Spreads, A Return to Mask Mandates

COVID-19 updates and news to know as of December 16, 2021.

As of December 16, 2021, there have been 50,181,003 COVID-19 cases in the United States. In the last 7 days, there have been 825,653 new cases identified (CDC)

Data from the CDC suggest that the Omicron variant of the SARS-CoV-2 virus is beginning to “eat into Delta’s dominance” in the US. Based on the spread of Omicron in other countries, it is anticipated that the current case count will dramatically increase in the coming weeks. (STAT News)

And as Omicron spreads, health experts are once again pushing for mask mandates. States like California and New York have taken heed of these recommendations, but according to NPR, states with mask mandates are, at the moment, outliers. (NPR)

As of December 14—just 2 years after the first cluster of COVID-19 cases was reported in Wuhan, China—800,000 Americans have died due to COVID-19. NPR spoke with Helen Y. Chu, MD, MPH, an immunologist and epidemiologist at the University of Washington, who was instrumental in identifying the first community spread cases of COVID-19 in the United States. (NPR)

A study from the University of Hong Kong found that the SARS-CoV-2 Omicron variant is capable of multiplying faster and infecting better than both the original SARS-CoV-2 and the Delta variant. The researchers noted that disease severity is determined not only by virus replication, but also by host immune response—which may lead to dysregulation known as a cytokine storm. They concluded that the “overall threat from [the] Omicron variant is likely to be very significant.” (University of Hong Kong)

Chicago Public Schools has announced an initiative to provide 150,000 take-home COVID-19 test kits in 309 schools across communities hit hardest by the pandemic. According to Chicago’s chief health officer, the city is currently in the middle of a “wicked post-Thanksgiving" surge. (NBC Chicago)

In the European Union, Omicron is expected to be the dominant variant by mid-January. Currently, 66.6% of the EU population is fully vaccinated. (Associated Press)

The CDC’s Advisory Committee on Immunization Practices (ACIP) is expected to meet on December 16 to vote on updated recommendations for use for the Johnson & Johnson COVID-19 vaccine. According to the agenda, the committee will hear data on thrombosis and thrombocytopenia syndrome (TSS), the rare—and serious—blood clotting condition that has been linked to the vaccine. (CNN)

Also on December 16, AstraZeneca announced that their long-acting antibody combination for the prevention of COVDI-19—tixagevimab co-packaged with cilgavimab (Evusheld)—"retained neutralizing activity against the Omicron SARS-CoV-2 variant” according to preclinical data. (AstraZeneca)