Speaking in the House of Commons this week, health and social care secretary Sajid Javid highlighted evidence that two doses of COVID-19 vaccine offer 'lower immunity against Omicron...when compared to the Delta variant'.
As a result, two doses of vaccine are 'less effective at reducing transmission in the community' of Omicron - which experts have warned is now spreading rapidly - the health and social care secretary warned.
Mr Javid cited research from Pfizer suggesting that a third dose of its COVID-19 vaccine 'neutralised the Omicron variant to levels that are similar to the impact of two doses against the original strain' - and emphasised the need for people to come forward to booster jabs.
However, analysis by GPonline of COVID-19 booster jab uptake across England shows the rollout of booster jabs to patients aged over 50 varies widely across the country.
In Fylde and Wyre CCG, in Lancashire, 77.1% of the population aged over 50 has received a booster or third dose of COVID-19 vaccine - the highest coverage of any CCG in England.
The CCG is one of only five out of 106 nationally to have completed booster or third-dose jabs in more than 75% of people aged over 50 by 5 December.
In North East London CCG, however, just 53.4% of the population aged over 50 had received a third dose or booster COVID-19 jab by 5 December.
London has lagged behind throughout the vaccination campaign, with coverage across the board behind the rates achieved in other areas - and three other London CCGs are in the bottom five for coverage of booster or third doses in over-50s.
North Central, North West and South East London CCGs have each delivered third doses or boosters to around three in five over-50s - with Manchester CCG at a similar level.
CCGs with the lowest uptake of booster and third-dose COVID-19 vaccination also have generally low uptake of first doses among 12- to 17-year-olds, and of second doses among over-18s - emphasising the regional gap in England's pandemic defences.
Uptake of first-dose vaccinations among people aged between 12 and 17 varies two-fold between CCGs across England, with just a third having received a first dose in some areas compared with nearly 70% in other areas.
Major gaps also remain in coverage of second doses among over-18s - with some areas having delivered two jabs to just three quarters of their adult population, compared with up to 95% coverage in other areas.
So it’s more important that we get our boosters than ever, available for all those eligible, and keep strengthening the defences that we’ve built.
Today we’ve opened booster bookings to seven million more people in England.
So people aged 40 and over - and those in high-risk groups - will be able to get their booster jab from three months after their second dose.