The UK medicines regulator has approved the Pfizer/BioNTech coronavirus vaccine for use in children aged 12 to 15, but the independent vaccination committee has not yet decided whether to extend the roll-out
The researchers noted that the most important thing is to ensure that vaccine protection remains high enough to keep as many people out of hospital as possible.
The Lancet study analysed antibodies in the blood of 250 healthy people who received either one or two doses of the Pfizer-BioNTech Covid-19 vaccine, up to three months after their first dose.