The UK has been told to prepare for one million omicron Covid cases by the end of the month.
The UK Health Security Agency said Wednesday that omicron is showing a significant growth advantage over the delta variant, meaning that it is likely to out compete in the U.K.
The UKHSA said that the assessment was based on the U.K. data showing increased household transmission risk, increased secondary attack rates, and increased growth rates compared to delta.
If the growth rate and doubling time continue at the rate we have seen in the last 2 weeks, we expect to see at least 50% of coronaviruses cases to be caused by omicron variant in the next 2 to 4 weeks.
The U.K. has recorded 568 confirmed cases of the variant, but the Health Secretary Sajid Javid told British lawmakers that the actual number of infections will be significantly higher.
The UK Health Security Agency estimates that the current number of infections is 20 times higher than the number of confirmed cases.
The U.K. could see a million infections by the end of the month, according to Javid.
The U.K. has a doubling time of cases of 2.5 days, according to Danny Altmann, professor of immunology at Imperial College London.
A fan wearing a face mask looks on during the Sky Bet Championship match between Forest and Cottager at the City Ground on October 24, 2021.
The immunology landscape regarding omicron is not as bad as it is with the delta variant.
He told CNBC that if you are an unvaccinated person or a two-dose vaccine holder, you have little protection against infections.
If you have booster or two doses, you are probably in the safe protective zone, and that is what the studies are showing.
The World Health Organization reported the omicron variant to them in November. Two days later, it was labeled a "variant of concern" by the WHO.
The variant has been identified in 57 countries across the world, and there are increasing cases of community transmission with no links to travel.
Experts and vaccine makers are trying to assess the variant's risk profile. They are focused on how fast it spreads, whether it causes more severe illness, and whether it will undermine Covid vaccines.
The omicron variant is more transmissible than the delta variant, but causes milder illness, and could undermine the effectiveness of Covid vaccines currently in use.
It is too early to conclude that omicron symptoms are weaker, according to the WHO technical lead. The WHO Director-General said that omicron could change the course of the epidemic.
A number of countries banned flights from southern African countries where the omicron variant was first detected, as many are already dealing with a surge in delta cases as winter approaches.
On Wednesday, the U.K. advised people who could work from home to wear masks and use Covid passes.
There have been several pieces of positive and negative news regarding the omicron variant this week, but global financial markets have rallied in recent days as traders bet that the omicron Covid variant's economic impact won't be as severe as initially feared.
Preliminary research shows that the omicron variant can undermine protective antibodies that were created by the vaccine.
The initial lab study showed that a third dose of vaccine is effective in fighting the omicron variant, but the effectiveness of the initial two-dose vaccine series fell significantly.
Bourla told CNBC that when they see real-world data, they will determine if the omicron is well covered by the third dose. I think we will need a fourth dose.
CNBC contributors contributed to the story.
