Amid the sudden surge in COVID-19 cases in Europe due to Omicron, the World Health Organisation's Europe head has advised the widespread use of boosters shots. "The booster is the single most important defence against Omicron," Hans Kluge said. Omicron has been detected in at least 38 of the 53 countries in Europe.

The new Omicron variant is already dominant in several of the European countries including Denmark, Portugal and the United Kingdom. "We can see another storm coming," Hans Kluge said. "Within weeks, Omicron will dominate in more countries of the region, pushing already stretched health systems further to the brink."

The World Health Organisation (WHO) data shows that in recent weeks Europe reported the highest number of COVID-19 cases compared to the population size anywhere. WHO officials had earlier warned of a further 700,000 deaths from the disease by March.

According to WHO's Europe Head, so far, 89% of the early Omicron cases in Europe were associated with common COVID-19 symptoms such as cough, sore throat and fever.  Most cases had been reported among adults in their 20s and 30s, spreading initially in cities at social and workplace gatherings, Kluge said.

The WHO official also warned that the volume of new COVID-19 infections could lead to more hospitalisations and widespread disruption to health systems and other critical services. Meanwhile, WHO said on Monday that Omicron is spreading faster than the Delta variant, causing infections in people already vaccinated or recovered from the disease.