People in the age group are being invited to book their first vaccine from this week.
Schools in England will open to more pupils on Monday, in the first phase of lockdown easing.
The existing recommendations are based on out-of-date evidence, the Royal College of Nursing says.
Parents are confident about children returning to school but worry about catching up, says survey.
Bennylyn Burke and two children had been missing from South Gloucestershire since 17 February.