The alarm was raised about the extraordinary number of completely unvaccinated people by the capital’s public health chief, Professor Kevin Fenton.
A City Hall health summit also heard that only 30 per cent of London children aged 12 to 15 had been vaccinated — the lowest rate in the country. Previously it was thought that the number of adult Londoners who had not come forward for a first jab had fallen below a million.
But Professor Fenton — Mayor Sadiq Khan’s top health adviser — told the London health board this week: “There are more than 2.9 million Londoners who still have not received their vaccine over the age of 16.”
By Thursday night, the number had fallen to 2,708,450 after about 200,000 jabs were administered in the most recent week. Professor Fenton said the problem was concentrated in nine boroughs, which accounted for 45 per cent of the unvaccinated population.
Hackney mayor Phil Glanville said 100,000 of his borough’s residents had not had a jab.
Boroughs such as Westminster, Newham, Brent, Hackney and Camden have the lowest first-jab take-up rates in the country, with a third or more of residents unprotected.
Professor Adam Finn, a member of the Joint Committee on Vaccination and Immunisation, said: “People who have not been vaccinated at all ought to be thinking really hard about whether they get a vaccine because they are a much bigger risk to us all and to themselves than anyone else.”
The high case rates in children — particularly those aged five to nine and 10 to 14 — have raised fears about more disruption this winter in schools.
Only 130,915 of the 425,353 London children aged 12-15 have been vaccinated. This means that almost three million Londoners eligible for a Covid vaccine may not have received it.
In south-east London, only 12,000 out of 85,000 eligible pupils in the 12-15 age cohort have been vaccinated.
In one borough, less than 10 per cent of pupils have come forward to have their jab in school, the Standard understands.
Only 442 of the capital’s 972 schools were visited by vaccination teams before the October half-term, with 65,000 jabs administered — despite the Government’s target of offering all pupils a single jab before the break.
Danny Thorpe, leader of Greenwich council, said: “There is no getting away from the fact the number of children and young people [vaccinated] is lower than everyone would like. School vaccination has been incredibly frustrating. It’s because there are real issues around the confidence of parents.”
Sharon White, chief executive of the School and Public Health Nurses’ Association, said school nurses were facing verbal and physical threats from anti-vaxxers.
She said a combination of issues was causing low uptake — in particular the “mixed messaging” from the Government and Joint Committee on Vaccination and Immunisation on the safety of jabs for children.
“I think it’s left a position where parents are quite confused what to do for the best,” she told the Standard. “That is set against the backdrop of school nurses not having time to spend with these parents to try to explain the risks so they can take an informed decision.”
Health chiefs are closely watching for any impact from soaring Covid rates on the Continent.
Overall, London is said to be doing better than the rest of the country in terms of having fewer hospitalisations and deaths, due to a combination of immunity from past infection and the protection offered by the vaccination programme.
The capital is also leading the way on third jabs, which now account for about 80 per cent of the 40,000 vaccinations a day being given in London.
Dr Vin Diwakar, medical director for the NHS in London, said: “Thanks to the massive ongoing effort from our staff and volunteers across the capital, the NHS is making great progress in protecting Londoners against Covid, with more than 13 million life-saving vaccination doses delivered so far, including over 1.3 million booster jabs to those eligible.
“There are over 400 Covid-19 vaccination sites across London, we continue working with schools, the Mayor, councils and community and faith leaders to ensure that all Londoners are in easy reach of the vaccine, so we would encourage anyone eligible who hasn’t yet taken up the offer of the jab to come forward as soon as possible to protect themselves and their loved ones.”
On Friday, in a boost for travellers, the Department of Health announced that the NHS Covid app would display proof of a third dose, as required for outbound travel to countries including Israel, Croatia and Austria.
Separately, pregnant women — one of the biggest groups of unvaccinated adults — were urged to get jabbed after a UCL and Great Ormond Street Hospital study found unborn babies may get Covid in the womb, although there was only a small risk.
NHS England disagrees with Professor Fenton’s figure and says that 1.2m Londoners aged 16 or older are unvaccinated.
This is because of different views about the size of London’s population.
NHS England prefers to use the Office for National Statistics estimate that London’s 16+ population is 7,149,28.
This is considerably lower than the 8,683,894 figure from the NHS’s National Immunisation Service database that is used by the UK Health Security Agency, the successor organisation to Public Health England.
Experts believe the “true” figure will lie somewhere between 1.2m and 2.7m but all parties accept there remains a huge challenge to convince unvaccinated Londoners to get jabbed.
People aged 40 to 49 are expected to be able to book their booster jab from next Monday, November 22.
A spokesman for the Mayor said: “In the past few weeks NHS London have written to millions of parents and explaining the benefits of the vaccine, addressing any concerns they may have and inviting them to book their child in for a jab.