The Pfizer Covid-19 jab is “100% effective and well tolerated” among children aged 12 to 15, a new study suggests.

Pfizer said it now plans to seek approval for use of the vaccine in this age group from regulators around the world and hopes youngsters will start to receive the jab before the next school year.

The pharmaceutical company said it plans to submit the data to the UK regulator – the Medicines and Healthcare products Regulatory Agency – within the next couple of months.

Researchers examined the use of the Pfizer/BioNTech vaccine in a trial of 2,260 teenagers in the US.

Half were given the jab and the other half were given a placebo drug.

There were no Covid-19 cases seen in the group who received the vaccine and 18 infections among those who did not.

Albert Bourla, chief executive of Pfizer, said: “We share the urgency to expand the authorisation of our vaccine to use in younger populations and are encouraged by the clinical trial data from adolescents between the ages of 12 and 15.

“We plan to submit these data to FDA (the US Food and Drug Administration) as a proposed amendment to our emergency use authorisation in the coming weeks and to other regulators around the world, with the hope of starting to vaccinate this age group before the start of the next school year.”

Ugur Sahin, chief executive and co-founder of BioNTech, said: “Across the globe, we are longing for a normal life. This is especially true for our children.

“The initial results we have seen in the adolescent studies suggest that children are particularly well protected by vaccination, which is very encouraging given the trends we have seen in recent weeks regarding the spread of the B.1.1.7 UK variant.

“It is very important to enable them to get back to everyday school life and to meet friends and family while protecting them and their loved ones.”

Pfizer said the jab “demonstrated 100% efficacy and robust antibody responses exceeding those reported in trial of vaccinated 16-25-year-old participants in an earlier analysis”.

Participants in the Phase 3 trial, conducted in the US, showed “strong immunogenicity” a month after the second dose of the jab.

It added that “administration was well tolerated, with side effects generally consistent with those observed in participants 16 to 25 years of age”.

All participants in the trial will be monitored for two years after their second dose.

Pfizer and BioNTech said they plan to submit the data for scientific peer review for potential publication.

Commenting on the news, Dr Stephen Griffin, associate professor at the University of Leeds, said: “In short, this is fantastic news.

“Demonstrating efficacy and safety in younger patients is an important step forwards in terms of enabling eventual population immunity against Sars-CoV2.

“It will enable a long term programme of school-based vaccination to be implemented following the initial rollout, ensuring that our population is well protected from the virus in the future.”

Dr Peter English, retired consultant in communicable disease control, added: “When the full, peer-reviewed papers appear – or when regulators receive the data directly from the companies – it will open up the way to extending vaccination to this age group (and likely to the younger age group referred to in the press release). It will be important to do this to achieve herd immunity.”

Meanwhile, the companies also announced they have dosed the first children in a trial assessing the safety and effectiveness of the jab in youngsters aged six months to 11 years.

The news comes after figures showed a slight rise in cases among youngsters after schools reopened.

In its latest weekly surveillance report, published last week, Public Health England said the rate for 10 to 19-year-olds stood at 100.7 cases per 100,000 in the seven days to March 21.

This was the highest rate across all age groups and was up week-on-week from 79.7.

Among five to nine-year-olds, the case rate rose from 39.9 to 63.5 per 100,000. But for children aged four and under, the rate had fallen from 34.9 to 32.4.

Currently, only children at very high risk of severe infection are offered a jab.

Oxford University is carrying out a clinical trial on children aged six to 17 to test the safety and efficacy of its vaccine in younger age groups, with initial results expected in the summer.

But Professor Adam Finn, of the Joint Committee on Vaccination and Immunisation, said on Wednesday that no final decisions has been made about vaccinating youngsters.