The UK’s COVID alert level has been raised to its second highest following a rapid increase in cases of the Omicron variant.

The country’s four chief medical officers have recommended to ministers that the UK moves to level 4 from 3.

The CMOs warn Omicron is spreading much faster than Delta and there is less vaccine protection against symptomatic disease from the new variant.

They also said that people are already in hospital due to Omicron and the number of patients is “likely to increase rapidly”.

On Sunday, the UK reported 1,239 additional confirmed cases of Omicron – the highest daily rise and nearly double the previous high recorded on Saturday.

That takes the total numbers of cases of the variant to 3,137 in the UK.

The alert level upgrade means health authorities think rates of transmission are high and pressure is being placed on healthcare services.

COVID: UK reports 1,239 additional Omicron cases – nearly doubling previous daily high

COVID-19: PM facing major revolt over coronavirus curbs, amid ‘authoritarianism’ warning

COVID-19: Daily lateral flow testing for double-jabbed contacts of coronavirus cases to start on Tuesday

It comes as Prime Minister Boris Johnson is set to give an address to the nation later this evening on the COVID vaccine booster programme.

The CMOs and NHS England’s Professor Stephen Powis said the emergence of Omicron “adds additional and rapidly increasing risk to the public and healthcare services”.

In a statement, they said: “Transmission of COVID-19 is already high in the community, mainly still driven by Delta, but the emergence of Omicron adds additional and rapidly increasing risk to the public and healthcare services.

“Early evidence shows that Omicron is spreading much faster than Delta and that vaccine protection against symptomatic disease from Omicron is reduced.”

They added: “Data on severity will become clearer over the coming weeks but hospitalisations from Omicron are already occurring and these are likely to increase rapidly.”

The medical officers say when vaccine protection is reduced – as is the case with Omicron – is it is “essential” that people top up with a booster jab.

They have said both booster vaccines (Pfizer and Moderna) increase the immune response substantially and show good effectiveness although with some reduction compared to Delta.

Here is what each alert level means:

Level 5 – The highest on the scale, this indicates there is a “material risk” of the NHS being overwhelmed.

Reaching this level would involve tighter social distancing measures.

Level 4 – This means the COVID-19 epidemic “is in general circulation” and that “transmission is high or rising exponentially”.

Level 3 – While this level also suggests the epidemic is “in general circulation”, it omits the statement “transmission is high or rising exponentially”.

It would mean a gradual reduction in social distancing measures and restrictions.

Level 2 – To shift to this level, the government guidance says the virus would be present in the UK, but that the number of cases and transmission is low.

It says this would then allow “no or minimal social distancing measures”, but with enhanced “testing, tracing, monitoring and screening”.

This level has not been reached since the system was introduced.

Level 1 – The level which the government eventually hopes to reach, this would indicate “COVID-19 is not known to be present in the UK”.

Related posts:

Ex-cabinet minister and Lib Dem peer Shirley Williams – one of the ‘Gang of Four’ – dies aged 90 Gap between first and second vaccine doses shrinks to eight weeks for over-50s amid variant fears Over-35s to be offered jabs in coming days as government urges those eligible to come forward Man who comforted victim of Plymouth shooting describes coming face to face with the gunman Schoolchildren to be offered lessons on consent after murder of Sarah Everard Laser weapons to be fitted on UK warships and armoured vehicles for first time ‘Speed of the essence’ in UK move from COVID plan A to plan B, warns WHO expert Gavin Williamson: A career politician whose removal as education secretary will be of little surprise to many Katie Price avoids jail after flipping car while drink-driving People in quarantine hotels to be told today when they can leave after travel red list scrapped ‘Bring it on!’: Johnson recovers his bounce as he vows to fight off the Tory rebels Work from home advice ends and face coverings no longer mandatory in classrooms in England