England will move to Plan B following the rapid spread of the Omicron variant in the UK.
“It’s not a lockdown, it’s Plan B,” the prime minister told a news conference.
He said moving to the tougher measures was the “proportionate and responsible” thing to do.
Mr Johnson said more is still being learned about new variant Omicron and the picture might get better, but that it “could lead to a big rise in hospitalisations and therefore sadly in deaths”.
Urgent work has been ongoing to understand the impact of the new variant with regards to vaccines, treatments and transmissibility. Early indications showed a large number of concerning spike protein mutations as well as mutations in other parts of the viral genome.
The most recent data suggests that Omicron has a very high growth rate and is spreading rapidly.
There are currently 568 cases confirmed across the UK and early analysis from the UK Health Security Agency suggests the doubling time could be as little as 2.5 to 3 days.
As seen in previous waves, a swift rise in cases can lead to a rapid rise in hospitalisations, which will quickly lead to pressure on the NHS. The data in South Africa is showing a rapid increase in hospitalisations.
Plan B measures will come into force while more data on vaccine efficacy and disease severity is assessed.
Plan B was set out in September and will help to slow the spread of the variant and reduce the chances of the NHS coming under unsustainable pressure while buying time to deliver more boosters.
While it is likely there is some level of reduced vaccine effectiveness against Omicron, it is still too early to determine the extent of this.
The government will continue to look closely at all the emerging data but vaccines remain our best line of defence and it is now more vital than ever that those who are unvaccinated come forward, and those eligible for their boosters book when called.
Today the NHS confirmed a huge expansion of the booster programme, with the National Booking Service now open to all those aged over 40 to book their jabs.
The dose interval has also been shortened from six months to three months, with those eligible now able to book a month in advance – two months after their second dose.
The vaccine programme will be supported by the continued development of world-leading treatments. Today the Prime Minister confirmed a new national study that will see 10,000 UK patients at risk of serious illness from Covid-19 given the treatment molnupiravir to treat their symptoms at home.
Testing will also be a vital tool in controlling the spread given the likely increased transmissibility of Omicron. As there is now demonstrated community transmission of Omicron, we intend to introduce daily contact tests for contacts of confirmed positive cases instead of the ten-day self-isolation period.
Everyone should test using a lateral flow device, particularly before entering a high-risk setting involving people you wouldn’t normally come into contact with, or when visiting a vulnerable person. Lateral flow devices remain free of charge and can be collected from local pharmacies.
From Friday 10 December, face coverings will become compulsory in most public indoor venues, such as cinemas, theatres and places of worship.
There will be exemptions in venues where it is not practical to wear one, such as when you are eating, drinking or exercising. For that reason, face masks will not be required in hospitality settings.
From Monday 13 December, those who can will be advised to work from home.
From Wednesday 15 December, and subject to parliamentary approval, the NHS Covid Pass on the NHS App will become mandatory for entry into nightclubs and settings where large crowds gather – including unseated indoor events with 500 or more attendees, unseated outdoor events with 4,000 or more attendees and any event with 10,000 or more attendees.
People will be able to demonstrate proof of two vaccine doses via the app. Having considered the evidence since the emergence of Omicron, proof of a negative lateral flow test will also be accepted.
Introducing Covid-19 status certification from next Wednesday will give businesses a week’s notice, as promised in the government’s proposals for introducing mandatory certification published in September.
A full list of guidance on these changes will be announced in the coming days. Face covering regulations will be laid in parliament tomorrow, with the remaining regulations laid on Monday 13 December.
Parliament will debate the measures next week, with a vote expected to take place on Tuesday 14 December.
The government will keep the data under constant review. The regulations are set to expire six weeks after implementation, with a review after three weeks.