Pupil self-isolation Covid impact 'not monitored' By Nick Triggle image captionThere have been worries too many pupils are having to self-isolate and lose time in school The government cannot say how many Covid cases in England are being prevented by sending pupils home from school to self-isolate. The BBC has been told it does not monitor how many children self-isolating end up getting the virus. It means the effectiveness of the policy cannot be fully judged. Some 279,000 children are currently being asked to isolate at home because they have had close contact with an infected person in school. That equates to 20 pupils being asked to self-isolate for every one confirmed case.