United Kingdom's medicines regulator on Friday approved Pfizer/BioNTech COVID-19 vaccine and said that it is safe for adolescents aged 12 to 15. The agency said that the call has been taken after a 'rigorous review', reported news agency AFP.

"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," said June Raine, head of the Medicines and Healthcare products Regulatory Agency.

The decision comes after a study published in the 'Lancet journal' noted that the Pfizer-BioNTech COVID vaccine is five times less efficient against Delta variant of coronavirus. The variant was first identified in India and is believed to be the reason behind the second deadly wave of COVID in the country.

Also Read: Delta COVID variant dominant in UK, may pose higher risk of hospitalisation

The study also indicated that levels of these antibodies that are able to stimulate an immune response against the virus are lower with increasing age.