Data from the UK coronavirus dashboard show 3,906 people aged 16 and 17 in the area had received two jabs by January 16 – some 57% of the age group.
A further 1,237 youngsters between 12 and 15 had also received two doses of a vaccine by that date – nine per cent of the age group.
That means 5,143 under-18s in Northumberland are double-jabbed – 25% of the age group.
They are among 14,315 (69%) who had received a first dose by January 16.
In England, 52% of 12 to 15-year-olds have had at least one dose of the Covid jab, including nine per cent who have received two.
The rates for 16 and 17-year-olds stood at 66% for one dose and 45% for two by January 16.
A Government spokesperson said: “The evidence is clear, vaccines are the best way to protect young people and their friends and family from Omicron."
Booster bookings for 16 and 17-year-olds, and for clinically vulnerable 12 to 15-years-olds are now being offered.
NHS vaccination programme lead for 12 to 15-year-olds, Nick Hulme, said: “The booster has been proven to give substantial levels of protection against Covid-19 and the new Omicron variant, so it is vital that our youngest and most at-risk get their top-up dose as soon as possible.