Cases drop for first time as Africa's fourth COVID-19 wave ebbs
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How Omicron Is Different Than Delta
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How Omicron highlights fading hope of herd immunity from COVID
By Julie Steenhuysen
Omicron might be the worst Covid gets when it comes to transmissibility, experts predict
By Jade Scipioni
COVID-19: How long is contagious period for Omicron, Delta?
By Catherine Schuster-Bruce