The UK reported a new spike of 12,133 Omicron cases,  the biggest daily increase since this variant was detected in the country, in the last 24 hours, taking the total tally to 37,101. The country, which registered 82,886 new Covid-19 cases on Sunday and 45 deaths within 28 days of a positive test, witnessed a 51.9% rise in fresh cases of infection over the last seven days till December 19, compared with the previous week, according to latest data released by  the UK government. The spike in fresh Covid-19 cases was mostly driven by the Omicron variant of coronavirus.  Omicron – the new SARS CoV-2 ‘variant of concern’ has already been reported in 89 countries and the number of cases is doubling in 1.5 to 3 days in areas with community transmission, the World Health Organization (WHO) said on Sunday.