New government guidance as of 1^st April 2022 –

Adults with the symptoms of a respiratory infection, and who have a high temperature or feel unwell, should try to stay at home and avoid contact with other people until they feel well enough to resume normal activities.

Children and young people who are unwell and have a high temperature should stay at home and avoid contact with other people. They can go back to school, college or childcare when they no longer have a high temperature, and they are well enough to attend.

Adults with a positive COVID-19 test result should try to stay at home and avoid contact with other people for 5 days, which is when they are most infectious. For children and young people aged 18 and under, the advice will be 3 days.