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European wave of Omicron sub-variant BA.2 foreshadows US surge
By John Burn-Murdoch, Leila Abboud & Oliver Barnes
How protected are we against Covid-19? Scientists search for a test to measure immunity
Omicron's 'stealth' subvariant BA.2 could go 'wild' in Europe before going global, top epidemiologist says
By Holly Ellyatt
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AstraZeneca COVID drug neutralises Omicron sub-variants in lab study
By Pushkala Aripaka, Aditya Soni & Kalluvila Sriraj
A Stress Test for America's New COVID Plan Is Coming
By Katherine J. Wu
Omicron BA.2 Variant Now More Than Half Of All New Covid Cases Across Large Swath In U.S., Per CDC
By Tom Tapp
What is the new COVID-19 variant BA.2, and will it cause another wave of infections in the US?
By Prakash Nagarkatti & Mitzi Nagarkatti
Scientists debate fourth Covid vaccine dose as Omicron cases rise
By Hannah Kuchler & Jamie Smyth