The UK Health Security Agency said the new guidance for children aged 12 to 15 had been taken as precautionary measure to reduce the risks of a rare type of heart inflammation.
Until now, parents have only been advised to wait a month for children who suffer a Covid infection to be vaccinated.
The new advice, following a review of evidence by the Joint Committee on Vaccination and Immunisation (JCVI), affects millions of children in a vaccine rollout that is already significantly delayed.
Comment: Unfortunately this vital information will come too late for those who have already been vaccinated.
Health officials had originally intended to complete the vaccination of secondary school children by the October half-term.
But fewer than four in 10 eligible children have so far had a jab, with just over one million of those aged between 12 and 15 in England having been vaccinated.
Comment: Interesting that they don't go into details of why that is.
More than half of children of secondary school age are estimated to have been infected with Covid since the start of September.
On Wednesday night, officials admitted the new advice may slow the rollout's progress amid concern it could undermine confidence.
Comment: And justifiably so.
But scientists said it was crucial that they were "honest with the public" about the uncertainties of the programme, including its "extremely small" risks and "modest benefits".
Comment: Honest!? The scientists may be attempting to be honest on this occasion, but the MSM and the government have been decidedly DISHONEST and manipulative throughout. It bears repeating that children are extremely unlikely to get severe COVID and the risks from the vaccine significantly outweigh any supposed benefits.
Twelve to 15-year-olds are currently only offered one dose of a Covid vaccine.
The precaution was taken because of evidence from other countries linking most cases of myocarditis to second jabs. However, most nations have shorter intervals between doses.
On Wednesday night, JCVI members said the rollout of jabs to adults in Britain - with a gap of between eight and 12 weeks - suggests that, with a longer interval, there is almost no risk of myocarditis.
Comment: Almost no risk or no risk? Why has Pfizer changed the formulation of its covid vaccine for children to include an ingredient that stabilises people suffering a heart attack? And why was the first oral blood-thinning drug to treat children 3 months to less than 12 years old with venous thromboembolism approved in June by the FDA?
The scientists said it seemed possible that, among those who had been naturally infected, a three-month gap might similarly reduce such risks.
Prof Adam Finn, a member of the committee, said the advice had been changed in the light of emerging evidence.
Comment: Which would've been discovered before the rollout had they conducted the proper safety trials for the normal period of 10 years.
"There are voices pushing for a much more black and white kind of line on this, that the public are going to be better off if we could give an absolutely clear and unequivocal message," he said.
"In a way we'd love to be able to do that, but it's not good if it's not true. Ultimately, the whole value of the programme, and of all of our other programmes is that we're honest with the public.
"There are uncertainties around it - the risks are extremely small, but they exist, and the benefits are modest."
Prof Finn also said it was likely that the committee would recommend second doses for 12 to 15-year-olds in the future.
Earlier this week, it announced that 16 and 17-year-olds will start to be offered second doses after a 12-week gap.
On Wednesday, officials stressed that the risks of heart inflammation remained very low. Health officials said most symptoms of myocarditis happen within a few days of vaccination, with most people recovering quickly.
Comment: What about the long-term effects?
However, if younger people experience any of the following symptoms after receiving a vaccination, they should call 111 or see a GP:
- Pain and/or tightness in the chest which may spread across the body.
- Pain in the neck that may spread across the shoulders and/or arms.
- Shortness of breath when lightly exercising or walking, or difficulty breathing when resting or feeling light-headed.
- Flu-like symptoms such as a high temperature, tiredness and fatigue, palpitations or an abnormal heart rhythm
- Feelings of nausea
Dr Mary Ramsay, the head of immunisation at the UK Health Security Agency, said: "The Covid-19 vaccines are very safe. Based on a highly precautionary approach, we are advising a longer interval between Covid infection and vaccination for those aged under 18.
"This increase is based on the latest reports from the UK and other countries, which may suggest that leaving a longer interval between infection and vaccination will further reduce the already very small risk of myocarditis in younger age groups."
Officials said natural infection would keep children protected for at least three months and would protect them for some time beyond that.
They said anyone over 18 should still take up their vaccine offer if it is four weeks since a positive case, given that the risk of complications from Covid rises with age.
RC