London, Oct 1 (IANS): Two doses of the Pfizer coronavirus vaccine can potentially protect children from thousands of cases of long Covid, suggests a new study.

The US Food and Drug Administration (FDA) has approved two doses of Pfizer-BioNTech Covid-19 vaccine to be administered to children ages 12 through 15, 21 days apart.

However, the chief medical officers in the UK, have approved only one dose of a Covid vaccine, to healthy children aged 12 to 15, over fears of the risk of myocarditis -- inflammation of the heart muscle.

Children with health conditions and those living with clinically vulnerable people are being offered two doses.

The new study, published in the Journal of the Royal Society of Medicine, suggests that the benefits of getting a second jab outweigh the risks "unless case rates are sustainably low", The Telegraph reported.

A team of researchers from the Queen Mary University of London, University College London and London School of Hygiene and Tropical Medicine, conducted a risk/benefit analysis of teenagers aged 12 to 17 getting both doses of the vaccine.

They used historic rates of hospital admission, intensive care support and death among children in England who had Covid-19.

The research estimates that hospital and ICU admissions, deaths and cases of long Covid averted over a 16-week period by vaccinating all 12-17 year olds in England.

"This analysis shows that, on clinical risks alone, vaccination is warranted for 12 to 17-year-olds in England," lead author Deepti Gurdasani, of Queen Mary University of London, was quoted as saying.

"While we wait to understand the long-term effects of Covid-19 on children, the precautionary principle advocates for protecting all children from exposure to this virus and vaccination is a crucial part of that protection," she added.

As of September 15, about 680 out of every 100,000 10-19-year-olds were contracting coronavirus every week, Sky News reported.

The study said if this rose to 1000 per week then full vaccination of 12-17-year-olds could "avert 4,430 hospital admissions and 36 deaths over 16 weeks".

However, if cases fell to 50 per 100,000, then an estimated 70 admissions and two deaths could be avoided over the same period.

"The benefit of vaccination in terms of hospitalisations in adolescents outweighs risks unless case rates are sustainably very low (below 30/100,000 teenagers/week)," said the study.

"Given the current high case rates in England, our findings support vaccination of adolescents against SARS-CoV-2," it added.

Further, the researchers said that double vaccination would avert 56,000, 16,000, or 8,000 cases (based on long Covid rates among 12-17-year-olds of 14 per cent, 4 per cent, and 2 per cent), the report said.