Boris Johnson announces tightening of Covid rules after Omicron reaches UK

The Omicron variant of coronavirus has been detected in the UK (Leon Neal/PA)

In the UK, mask rules will be mandatory in shops and on public transport, Omicron contacts will have to self-isolate and new arrivals will have to quarantine until they test negative for coronavirus after two cases of the concerning new Omicron variant were detected.

Boris Johnson warned the new variant could reduce the effectiveness of vaccines, as he announced a strengthening of England’s rules at a Downing Street press conference, after the infections were identified in Nottingham and Brentwood in Essex.

In an attempt to slow the spread, the UK Prime Minister announced “temporary and precautionary” measures to be reviewed in three weeks, alongside a “boost” to the booster campaign.

The UK Health Security Agency confirmed the cases, which are both believed to be connected and linked to travel to southern Africa, after genomic sequencing overnight.

The individuals and their households were ordered into self-isolation and targeted testing was being carried out in areas where they are thought to have been infectious

Malawi, Mozambique, Zambia and Angola will face travel restrictions from Sunday, when they will join South Africa and five other neighbouring nations on England’s red list.

Mr Johnson said details of the "tightening up" of the mask rules will be outlined by Health Secretary Sajid Javid "in the next day or so".

But Downing Street said they will become mandatory in shops and on public transport in the coming week, though they will not be required in pubs and restaurants.

To slow the "seeding" of the virus in the UK, Mr Johnson said anyone who enters the UK must now take a PCR test by the end of the second day of their arrival and self-isolate until they receive a negative result.

But the UK Prime Minister said border measures can “only ever minimise and delay the arrival of a new variant rather than stop it all together”, so all contacts with a suspected case of the new variant will have to isolate for 10 days, regardless of their vaccination status.

We will also go further in asking all of you to help contain the spread of this variant by tightening up the rules on face coverings in shops and on public transport.

Scotland and Wales said they would mirror the border restrictions.

Mr Johnson said they will be reviewed "in three weeks", adding: "At that point we should have much greater information about the continuing effectiveness of our vaccines."

While the effectiveness of vaccines against Omicron is currently unclear, Mr Johnson said there are “good reasons for believing they will provide at least some measure of protection”.

He said: “We’re going to boost the booster campaign” by asking the Joint Committee on Vaccination and Immunisation (JCVI) to consider giving boosters to “as wide a group as possible as well as reducing the gap” between second doses and the booster.