A 'COVID-19 response' document published earlier this week setting out the UK's roadmap to ease lockdown confirms that in addition to offering first doses of vaccine to the entire adult population - around 53m people UK-wide - by 31 July, the government is planning a booster campaign to offer patients a third dose of vaccine - potentially starting from autumn.
This could see the UK deliver 106m first and second doses by the end of October - in addition to millions more 'booster' doses by the end of the year, as part of a programme that is likely to become part of the annual NHS cycle.
Confirming plans for booster jabs, the government COVID-19 response said: 'The government is planning for a revaccination campaign, which is likely to run later this year in autumn or winter. Any revaccination is likely to consist of a single "booster" dose of a COVID-19 vaccine: the ideal booster may be a new vaccine specifically designed against a variant form of the virus. Over the longer term, revaccination is likely to become a regular part of managing COVID-19.'
The government declared earlier this month that its target of offering a first dose to all 15m people UK-wide in the first four priority groups identified by the Joint Committee on Vaccination and Immunisation (JCVI) was met two days early, on 13 February. The target was met after GP-led sites delivered a mammoth 10m jabs in a single month.
Almost 18m people UK-wide have now received at least one dose of COVID-19 vaccine, with around 75% of jabs delivered by GP-led primary care network (PCN) sites.
GP-led sites are currently focusing on offering first doses of vaccine to patients in cohort 6 - those aged 16-64 with underlying health conditions - and will ramp up second doses for patients vaccinated in the first wave from March.
Patients in JCVI cohorts 1-4 - 15m in total UK-wide - should have received a second dose by mid-May. Those in cohorts 5-9 - a further 17m UK-wide - should have been offered a first dose by 15 April and a second dose by mid-July.
JCVI priority groups
The 21m UK adults outside the priority cohorts should receive a first dose by 31 July and a second dose by the end of October.
Data on healthcare workers published this week suggests that a single dose of Pfizer/BioNTech vaccine 'reduces the risk of catching infection by more than 70%' and that after two doses this rises to 85%.
Public Health England (PHE) said the findings provided 'strong evidence' that the vaccine could 'interrupt virus transmission' by stopping people from becoming infected - in addition to reducing risk of death or hospitalisation.
PHE added that early data suggested people who did become infected after receiving a single dose of vaccine were 'far less likely to die or be hospitalised'.
It said: 'Overall, hospitalisation and death from COVID-19 will be reduced by over 75% in those who have received a dose of the Pfizer-BioNTech vaccine.'
The findings come after early data from Scotland suggested that four weeks after administration of a first dose, risk of hospitalisation was reduced by up to 85% by the Pfizer/BioNTech vaccine and up to 94% by the Astra Zeneca vaccine.