[11] Additional sites, including large venues such as sports stadia, entered the programme from 11 January 2021, with seven mass vaccination centres opening in England initially and seven in Wales.

[12] New guidance for allergy sufferers, antibody tests, new variants of SARS-CoV-2 (B.1.1.7 and B.1.617) and the use of the AstraZeneca vaccine in younger adults have been issued throughout the programme.

On 28 November 2020 the new role of Parliamentary Under-Secretary of State for COVID-19 Vaccine Deployment was set up within the Department of Health and Social Care in the Government of the United Kingdom, with Nadhim Zahawi the first to take office.

The first batch arrived in the UK the next day and was initially stored at an undisclosed central hub before being distributed to hospital vaccination centres across the country.

[42] In clinical trial subjects without HIV infections, the vaccine was also 60% effective against the 501.V2 variant, a SARS-CoV-2 strain first detected in South Africa.

[32] England Health Secretary, Matt Hancock said this was a "pivotal moment" in the programme as this vaccine was easier to transport and store, requiring only ordinary fridge temperatures.

[71] On 19 March, Prime Minister Boris Johnson received his first dose of the AstraZeneca vaccine at St. Thomas' Hospital.

The vaccine was administered on Miss Taylor, an unpaid carer from Ammanford, at Glangwili General Hospital, Carmarthen.

"[78] As of 16 June 2021[update] it was expected that vaccination would become mandatory for those working in aged care (excluding those medically exempt).

[79][80] The taskforce was formed in May 2020 to lead efforts to develop, manufacture and procure vaccines for the UK and globally,[81] and was led until the end of 2020 by biotech venture capital manager Kate Bingham.

[85] Services contractor Serco has a role in the deployment, as part of a contract which was extended for six months in June 2021 at a cost of £424 million.

[31] Despite this, Margaret Keenan, who was the first person outside of trials to receive a dose of the Pfizer–BioNTech vaccine, returned to hospital on 29 December 2020 for her follow-up injection.

[88] The new plan to increase the gap between first and second doses from 3 to 12 weeks was criticised as "unfair" by the British Medical Association (BMA) on 31 December 2020, as appointments booked for 4 January 2021 or later would have to be rescheduled.

During his address announcing England's third national lockdown on 4 January 2021, Boris Johnson indicated a preliminary target for the vaccination programme, saying:[70] By the middle of February, if things go well and with a fair wind in our sails, we expect to have offered the first vaccine dose to everyone in the four top priority groups identified by the Joint Committee on Vaccination and Immunisation.He went on to confirm this would include all elderly residents of care homes and indeed everyone over the age of 70, as well as all frontline health and social care workers, and all those who are "clinically extremely vulnerable".

Vaughan Gething, Minister for Health and Social Services in the Welsh Government, matched England's targets by announcing that all people in groups 1–4 would be offered a first dose by mid February.

[93] Extrapolating from these figures, Sky News estimated that supply for the UK overall would be sufficient to meet the British Government's aim of immunising all 15 million priority individuals in the country by mid-February, and vaccinating all adults in Britain with their first dose by mid-July.

[94] Polish group Omni Calculator developed a tool which estimates when individuals will receive the vaccine, based on age, employment, and health status.

[98][99] "People with underlying health conditions which put them at higher risk of serious disease and mortality" is defined as:[100] [94] The JCVI released an interim statement on 26 February 2021 regarding the rollout of the vaccine in Phase 2.

The order therefore in Phase 2 is as follows:[101] The JCVI also noted that males from BAME backgrounds and those with a BMI over 30 were at an increased risk, and therefore stated that it "strongly advises that individuals in these groups promptly take up the offer of vaccination when they are offered", with local officials advised to "promote vaccination in these groups".

[94][101] On 19 July 2021, the vaccine rollout was expanded to vulnerable adolescents from the age of 12 and young people in the three months prior to their 18th birthday.

[105] However, the UK's chief medical officers agreed to the rollout of a single dose of the Pfizer vaccine to this age group on 13 September in order to reduce disruption to education.

[116] As of 13 October 2021[update], a cumulative total of 49,252,939 people had received the first dose: 41,263,377 in England; 1,316,225 in Northern Ireland; 4,270,126 in Scotland and 2,403,211 in Wales.

"Hundreds" of residents received the first dose in seven care homes in Slough, Aintree, Herne Bay, Thanet, Chalfont St Peter, Droitwich and Cheltenham.

[122] Seven mass vaccination centres were initially opened in Wales with that number increasing to 34 by February alongside 17 acute and community hospital sites.

[123] High street pharmacies in England started to administer the vaccine from 14 January 2021, with 6 chosen for the roll out initially.

YouGov's first survey on the subject in the middle of November 2020 suggested that 15% of British adults would refuse to get a COVID-19 vaccine which had fallen to just 6% (the lowest of any country polled) by April 2021.

[133] Though a large majority of people in all social groups were willing to take the vaccine, polling suggested that some demographics were more likely to display reluctance than others.

[133] Though the previously cited survey sampled public opinion in Great Britain (England, Scotland and Wales) one poll conducted in September 2021 suggested that the level of vaccine hesitancy in Northern Ireland was fairly high in comparison.

[136] Polling at around this time suggested that 85% of British voters felt their government had handled the vaccine rollout well in comparison to less than a fifth of their French and German counterparts.

[138] The 'Mood of the Nation 2021' report by the consultancy firm BritainThinks based on research conducted in October and November 2021 found that whilst the optimistic mood around COVID-19 of the summer had rebaited the successful vaccine rollout remained one of few present day subjects which the general public in the UK cited as providing a sense of national pride.