A small number of schools in the town have this weekend acted fast to advise some staff, pupils and families to isolate following the emergence of positive Covid-19 cases.
Middlesbrough Council has praised the response of the schools and thanked families for their understanding.
All schools have risk assessments in place and are aware to follow clear protocols on reporting cases among staff or pupils.
Parents of children required to isolate as a precautionary measure have been contacted directly. Children should continue to attend school unless they are informed otherwise.
Cllr Mieka Smiles, Executive Member with responsibility for Education and Skills, said: "It's only natural for parents and carers to be anxious about Covid, but they can be assured our amazing schools have worked so hard to put robust response plans in place.
"This weekend we've seen schools respond rapidly after learning of positive cases among staff or students.
"All Middlesbrough schools will follow Public Health England advice to the letter and act quickly to take the necessary action.
"We understand there will be frustration about further interruptions to classroom learning, but health and safety will always come first.
"The disruption is absolutely no reflection on the hours of hard work dedicated teachers have put in to welcome back pupils.
"All our schools are following protocols designed to keep children and their families safe.
"Unless you are notified otherwise, you must continue to ensure your children attend school so they can get the education they deserve and build a happy future."
Schools are aware to contact Public Health England's North East Health Protection Team in the event of positive cases or concerns over levels of absence.
The Health Protection Team will work with schools to identify the correct response and issue advice around isolation where necessary.
Public Health England will liaise with the Council's Director of Public Health should further action be required.
- For the latest local updates and information, visit middlesbrough.gov.uk/covid19
For information on local help and support, visit Help Boro at www.middlesbrough.gov.uk/helpboro or call Middlesbrough Council's support line 01642 729777
The latest advice from Government and Public Health England can be found at https://www.gov.uk/coronavirus