British Prime Minister Boris Johnson announces that the government will implement its "Plan B" Covid measures due to the rapid transmission of the Omicron variant.
Mandatory Credit: Adrian Dennis/WPA/Pool/Getty Images
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UK scrambles for booster shots and tests amid fears of Omicron 'tidal wave'
The United Kingdom's Covid-19 response was under pressure on Tuesday, with the National Health Service (NHS) website crashing due to demand for booster appointments, lateral flow test kits no longer available online and long queues at vaccination walk-in centers.
