Britain stated on Monday that the Omicron variant of coronavirus was spreading at a "phenomenal rate" and accounted for roughly 40% of all cases in London, and that people who have been double-jabbed should obtain an additional dose of the vaccination.

Since the first cases of the Omicron variant were discovered in the UK on November 27, Prime Minister Boris Johnson has imposed stricter restrictions and warned the country on Sunday that a "tidal wave" of Omicron was on its way.

Britain claims that unless action is taken, a million people could be infected with Omicron, which scientists warn can still infect those who have been double-vaccinated, by the end of the month.

"What we now know about Omicron is that it's spreading at a phenomenal rate, something we've never seen before, and cases are doubling every two to three days," Health Secretary Sajid Javid said.

UK health secretary warns 'pandemic is not over'

According to data released on Friday, vaccine efficacy against symptomatic infection against Omicron was significantly reduced with just two doses, but a third dosage increased protection to more than 70%. 

Despite the fact that no deaths have been recorded in England and only 10 people have been hospitalised with the variant, Javid believes Omicron is responsible for approximately 40% of infections in London.

While the variant's symptoms may be milder, he believes that unless the government acts, the health-care system will be swamped.

"Even if a virus is mild, a small percentage of a very big number of people might still equal a high number of hospitalisations," Javid explained. "Two doses are not enough, but three doses still provide substantial protection against symptomatic infection."