Grey-Bruce Health Unit officials say hundreds of students in Grey-Bruce have yet to disclose their immunization records.
As of Tuesday, 707 students remained on the list.
The health unit says parents have up until Monday to provide the information. If they fail to do so, their child may be suspended for 20 school days.
Around 1,700 students were on the list back in March.
Public Health officials say in many cases, children have received the required immunization from their healthcare provider, but have yet to notify them.
Officials ask parents of students on the list to call Grey-Bruce Public Health, at 519-376-9420 or 1-800-263-345,6 and speak with a nurse about their child’s immunization record.
GBHU's are currently working to contact the students, and their parents, still on the list.
"The objective of the Immunization of School Pupil’s Act (ISPA) is not to suspend students from school but rather to ensure the school population is as healthy and protected as possible," says Sarah Ellis, a program manager for vaccine preventable diseases at the Grey Bruce Health Unit, in an email exchange.