UK scrambles for booster shots and tests amid fears of Omicron 'tidal wave'

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.

London (CNN)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.

In the run-up to a holiday season that the British government promised would return to normality after last year's heavily restricted affair, a weary nation is instead being wracked by a new crisis: Omicron.
The scramble for booster shots and tests comes just days after UK Prime Minister Boris Johnson announced a slew of new Covid-19 measures in the face of an incoming "tidal wave" of infections from the Omicron variant.
    Omicron has left one person dead in the UK and prompted warnings it could surpass the Delta variant to become dominant in the country by Christmas. Johnson has told people to "set aside" the idea that the variant is mild.
      Britain's beleaguered leader faced a major test of his authority on Tuesday, with members of his own Conservative party rebelling against measures on working from home, Covid passports and mask-wearing in a vote in Parliament. He was forced to rely on support from the opposition Labour Party to pass the new restrictions, which are a significant departure from the government's pandemic response in recent months. Johnson lifted all Covid-19 rules on "freedom day" in July and has until now resisted the more robust mitigation measures imposed in parts of Europe, like vaccine passports and mask mandates.
      The Prime Minister is also embroiled in a scandal over reports that Downing Street held a number of staff holiday parties last winter, when the rest of the UK was living under strict rules banning social mixing. He has been forced to deny that he fast-tracked "Plan B" Covid rules in order to distract from his political woes.
      Opening the debate in Parliament on the new Covid regulations Tuesday, UK Health Secretary Sajid Javid said that though the measures were not ones he would like to put in place, the situation demanded them. "As we look ahead to a winter with Omicron in the midst, the measures before the House [of Commons] today will fortify our natural defenses and guard the gains that we've all made against this deadly virus," Javid said.
        Scientists have never seen a variant that can spread so quickly and the growth in cases of Omicron in the UK is now mirroring the rapid increase in South Africa, Javid said, warning that the observed doubling time was two days. Until recently, ministers had said that cases were doubling every two to three days.
        So far, 10 people in England have been hospitalized with the variant, the health secretary said, warning that even if Omicron turned out to be less severe overall than the Delta variant, its greater transmissibility risks overwhelming the health service, which is already stretched to its limits.
        The health secretary added that there may now be as many as 200,000 Omicron infections a day -- a figure that the UK Health Security Agency (UKHSA) said was based on modeling -- with the strain accounting for 20% of cases in England.
        Recent analysis by the UKHSA has shown that two doses of AstraZeneca and Pfizer-BioNTech vaccines provided lower levels of protection against symptomatic infection from Omicron when compared with the Delta variant, but effectiveness rose considerably in the period after a booster dose -- 70% to 75% protection against mild disease.
        Javid described the "national mission" to get as many people vaccinated as quickly as possible, calling it "a race between the virus and the vaccine."
        The British government has insisted that its new booster drive, which aims to deliver third doses to every adult by the end of December -- a month earlier than planned -- is the best way to stop the spread of cases and avoid imposing further restrictions.
        NHS staff are being redeployed to accelerate the booster vaccination effort, postponing some urgent appointments and elective surgeries until the new year to prioritize third shots.
        More than 500,000 booster and third doses were deployed on Monday, according to government data. Around 45% of people aged 18 and over are now estimated to have received a third dose, according to analysis by the PA Media news agency.
        Commuters at London's Kings Cross station after the return of the mask mandate.