A new trial is to test how well the Oxford-AstraZeneca coronavirus vaccine works in children.
Some 300 volunteers are expected to take part, with the first vaccinations in the trial taking place later in February.
Researchers will assess whether the vaccination will produce a strong immune response in children aged between six and 17.
The vaccine is one of two being used to protect against serious illness and death from Covid in the UK, along with the Pfizer-BioNTech jab.
As many as 240 children will receive the vaccine – and the others a control meningitis vaccination – when the trial gets under way.
Volunteers who live near one of the four study sites – the University of Oxford, St George’s University Hospital, London, University Hospital Southampton and Bristol Royal Hospital for Children – are being asked to sign up.
Those interested in taking part will be expected to complete a short questionnaire.