After the UK’s Chief Medical Officers decided to raise the Covid Alert Level from Level 3 to Level 4, Prime Minister Boris Johnson has issued a personal appeal calling for people to “get jabbed”.

“A tidal wave of Omicron is coming,” Mr Johnson said as he announced that all adults in England are to be offered a booster jab by the end of the year. The devolved administrations have also agreed to accelerate vaccinations.

Recent data suggests that vaccine efficacy against symptomatic infection is substantially reduced against the Omicron variant with just two doses, but a third dose boosts protection back up to over 70%.

From Monday 13 December, adults over 30 will be able to book online through the National Booking System (available at https://www.nhs.uk/conditions/coronavirus-covid-19/coronavirus-vaccination), and all over 18s will be able to do so from 15 December.

Some walk-in appointments will be available from the earlier date for over 18s, dependent on location. If there are long queues or all slots have been booked, people are encouraged to be patient and keep trying, or to book online.

All primary care services will now focus on urgent clinical need and vaccines and some non-urgent appointments and elective surgeries may be postponed until the New Year while every adult in the country is jabbed, the Prime Minister explained.

He also said that there will be increasing opening times for vaccination sites, to seven days a week with more appointments early in the morning, in the evening and at weekends.

In addition, 50 military planning experts will help co-ordinate the national effort by supporting the NHS with logistics of the rollout.