UK regulators today followed the EU, the USA and Canada in saying the Pfizer coronavirus vaccine is safe for children over the age of 12.
It opens the door for a rollout over the summer, with the Medicines and Healthcare products Regulatory Agency (MHRA) saying it is satisfied jabs are safe and effective.
The ruling follows a study of more than 2,000 children, with results branded "extremely positive".
The Pfizer jab, which has previously been approved for 16 and 17 year olds, is the first vaccine to be permitted for under-16s in the UK.
It is now down to the Joint Committee on Vaccination and Immunisation (JCVI) to set out a timetable for children to be inoculated.
When will children aged 12 to 15 be vaccinated?
This has not been decided yet - but it won't be before next month.
The MHRA this morning said it would be for the Joint Committee on Vaccination and Immunisation (JCVI) to give the green light to the jab for 12-15 year olds and to set out a timetable.
In a statement the Department of Health and Social Care said: “The government has asked the independent experts at the Joint Committee on Vaccination and Immunisation (JCVI) to advise whether routine vaccination should be offered to younger people aged 12 to 17.
“We will be guided by the expert advisors and will update in due course.”
What has the Health Secretary said?
On May 17 Matt Hancock told the House of Commons that the rollout will not start until at least July.
He said that there are enough supplies to offer it to children, subject to approval.
The Health Secretary told MPs: “We have procured enough Pfizer to be able to offer it to children should it be approved here...
"We have a couple of months before we need to make and operationalise a decision, and we need to be very careful and sensitive about whether and how to offer it to children.”
Back in February he said that although children rarely suffer the worst effects of Covid, vaccinating under 18s would have a significant impact on transmission - making it safer for everyone.
He told Sky's Sophie Ridge on Sunday: "There are two points here; one is that it absolutely must be safe, specifically for children, so that is being currently investigated.
"And the second is - because children very, very rarely get symptoms and serious illness from the disease - the value, the importance of vaccinating children is to try to stop the spread of the disease and obviously that's something - the impact of the vaccine on stopping transmission is something - that we have early evidence of.
"It looks like the first jab reduces your impact of transmitting the disease by about two-thirds - but we need more evidence on that as well."
Have any other vaccines been approved for children in the UK?
Not yet.
In December last year, the Pfizer vaccine was approved for 16 and 17 year olds in the UK, but all the others currently approved are only available to over 18s.
The JCVI advises that those aged from 16 to 18 should be offered a Pfizer jab if they are clinically vulnerable.
Widespread vaccination of under 18s is not currently underway.
The Oxford/AstraZeneca is only licensed for over 18s, as is the Moderna vaccine.
Moderna has said that studies show its jabs are safe and effective for children between 12 and 15.
Are children in other countries being vaccinated?
The US began inoculating young adolescents in May after its Centre for Disease Control and Prevention (CDC) approved the Pfizer jab for those aged 12-15. More than 600,000 children have been vaccinated so far.
The jab has also been approved for emergency use in Chile, Canada, Japan, the Philippines, Israel and Dubai and the European Union.
Germany and Poland are both set to start vaccinating children in this age group next week, with France also set to start inoculating teenagers this month.
Marco Cavaleri, the EMA's head of vaccine strategy, last week said studies had shown the jabs are "highly preventative" for coronavirus in children.
He added: "From a safety perspective, the vaccine was well tolerated and the side effects in this age group were very much similar to what we have seen in young adults and not raising major concerns at this point in time."
The US Food and Drug Administration (FDA) described the approval for children "a significant step in the fight against the Covid-19 pandemic".
What did regulators say today?
De June Raine, chief executive of the MHRA, said: “We have carefully reviewed clinical trial data in children aged 12 to 15 years and have concluded that the Pfizer/BioNTech COVID-19 vaccine is safe and effective in this age group and that the benefits of this vaccine outweigh any risk.
“We have in place a comprehensive safety surveillance strategy for monitoring the safety of all UK-approved COVID-19 vaccines and this surveillance will include the 12- to 15-year age group.
“No extension to an authorisation would be approved unless the expected standards of safety, quality and effectiveness have been met.
“It will now be for the Joint Committee on Vaccination and Immunisation (JCVI) to advise on whether this age group will be vaccinated as part of the deployment programme.”
How did the trials work?
More than 2,000 children were involved in the UK's clinical trial, the chairman of the Commission on Human Medicines said.
Professor Sir Munir Pirmohamed said: "We have concluded that based on the data we have seen on the quality, effectiveness and safety of the vaccine, its benefits do outweigh any risk.
"The MHRA will continue to scrutinise all of the suspected side effects data received through the rigorous surveillance programme in place through the Yellow Card scheme and other safety surveillance measures for all of the Covid-19 vaccines used in the UK."
He said more than 2,000 children had taken part in the study, and there had not been a single case of coronavirus in the seven days after they were vaccinated - compared to 16 in a group given a placebo.
Prof Pirmohamed continued: "In addition, data on neutralising antibodies showed the vaccine working at the same level as seen in adults aged 16-25 years. These are extremely positive results."
How effective is the Pfizer vaccine?
A study, involving more than 2,000 adolescents in the US, has shown the jab to be safe and effective in 12 to 15-year-olds.
The trial investigators said the Pfizer vaccine was 100% effective at preventing Covid-19 disease, although the true rate could be between 75% and 100%.
In adults, phase three clinical trials have shown the vaccine to be around 95% effective in preventing people from developing coronavirus symptoms.
