More than 580,000 18 and 19 year olds in England have not had a MenB jab, UKHSA said on Thursday, as the first-dose offer ends on 31 December 2026.
Figures up to 31 October show that 28.2 per cent of the age group, or 228,297 of 809,957 eligible people, have had a first dose of the free vaccine.
Of those who have started the course, 68.8 per cent (157,169 people) have also had a second dose, about seven in 10.
The agency said the true number vaccinated is likely to be a little higher, because the offer also covers older students up to the age of 25. Uptake data for that group is due in the coming months.
Dr Shamez Ladhani, a consultant epidemiologist at UKHSA, said only just over a quarter of 18 and 19 year olds had been protected, and asked people not to forget the deadline during holiday events. "Please don’t leave it until the end of term," he said, adding that parties and gatherings increase mixing among young people and the risk of meningococcal disease spreading.
Public health minister Dame Diana Johnson urged everyone who has not yet had the jab to come forward for both doses and be "properly protected this Christmas".
Two doses, 28 days apart, with a second until 31 March 2027
The one-off programme is open to everyone born between 1 September 2007 and 31 August 2008. It also covers people under 25 who started university or residential further education for the first time this autumn.
Students can get the vaccine at local pharmacies and book through the NHS website.
Two doses are needed, at least 28 days apart. Anyone who gets a first dose before the deadline can have a second until 31 March 2027.
Offer began on 20 July after an outbreak that killed two people
The programme began on 20 July 2026 in response to an outbreak of meningococcal disease in Kent that began in March.
That outbreak was linked to a single nightclub in Canterbury over one weekend. It saw 21 people diagnosed in one week, nine of them needing intensive care, and two people died.
UKHSA says outbreaks in Kent, Dorset and Berkshire this year caused three deaths in total. It says genome research on the Kent bacteria shows that highly invasive strains can emerge suddenly and unpredictably, so similar outbreaks could occur again.
First-year university students face a risk around seven times higher than people of a similar age who do not go to university, according to UKHSA data.
Coverage was 26.6 per cent on 20 September
An earlier interim report, covering only those who were in school year 13 last year, put first-dose coverage at 26.6 per cent (212,549 of 799,840) up to 20 September. The latest figure uses a slightly different base, the whole 18 and 19 year old group.
The interim report found wide gaps. Coverage ranged from 21 per cent in London to 31.6 per cent in the South East. By deprivation it ranged from 11.8 per cent in the most deprived areas to 45 per cent in the least deprived.
Young women (31.5 per cent) were more likely than young men (21.9 per cent) to have had a first dose.
Caroline Temmink, NHS Director of Vaccination, said the offer "remains in place at high street pharmacies across the country" and encouraged anyone eligible, particularly those starting university for the first time, to come forward.
UKHSA publishes monthly coverage reports for England, broken down by region, integrated care board, deprivation, ethnicity and sex.