Masks will be mandatory in shops and on public transport, contacts of confirmed cases of the Omicron variant will have to self-isolate and new arrivals will have to quarantine until they test negative for Covid-19 under tightened coronavirus rules in England.
The changes come after two cases of the new Omicron variant, designated a variant of concern by the World Health Organisation (WHO), were detected in the UK nation on Saturday.
British prime minister Boris Johnson warned the new variant could reduce the effectiveness of vaccines, as he announced the rules at a Downing Street press conference, after the infections were identified in Nottingham and Brentwood in Essex.
"There is a reasonable chance that at least there will be some degree of vaccine escape with this variant," England's chief medical officer Chris Whitty told the press conference, speaking alongside Mr Johnson.
In an attempt to slow the spread, Mr Johnson announced “temporary and precautionary” measures to be reviewed in three weeks, alongside a “boost” to the booster vaccine campaign.
'We need to buy time'
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: “We need to take targeted and proportionate measures now as a precaution while we find out more.
“First we need to slow down the seeding of the variant in this country, we need to buy time for our scientists to understand exactly what we’re dealing with, and for us to get more people vaccinated, and above all to get more people boosted.”
But Mr Johnson 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.
COVID UPDATE: Face coverings will become compulsory on public transport and in shops. Not including hospitality. pic.twitter.com/pq3TdftcOB
— UK Prime Minister (@10DowningStreet) November 27, 2021
“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,” Mr Johnson said.
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 UK's 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.
Mr Johnson added that he still believes the UK is in a "much, much stronger position" to tackle the newly identified variant because of its vaccination programme.
"And it's in order to retain that strong position that we're taking the sensible precautionary steps that we are taking today," he said.
Mr Johnson added he was confident that Christmas this year would be "considerably better" than the last one, when the government introduced a lockdown to try to stem the spread of Covid-19.