The U.S. has recorded over 800,000 deaths from COVID-19 since the start of the pandemic. On Tuesday, a group of lawmakers marked the sobering milestone with a moment of silence on the steps of the U.S. Capitol.

This comes as the World Health Organization warned the Omicron coronavirus variant is spreading at an unprecedented rate and is likely already present in most countries. While early data show Omicron appears to cause less severe illness, it may be more resistant to vaccines. U.S. officials say it could soon become the dominant variant. In upstate New York, Cornell shut down its Ithaca campus after over 900 COVID cases were detected over the past week. Many of the infections were of the Omicron variant in fully vaccinated students.

Meanwhile, the head of the European Union also warned Omicron cases were doubling every two or three days, and the variant is expected to become dominant in Europe by mid-January. On Tuesday, Greece recorded its second-highest daily death toll since the start of the pandemic, with 130 fatalities.

In medical news, Pfizer said Tuesday its antiviral pill could reduce severe illness and death by nearly 90% if given within three days of the start of symptoms and that it is expected to work against the Omicron variant. The FDA could approve its use within days.