Lambton Public Health is reminding caregivers that time is running out to "Call the Shots."
In January, about 2,800 letters were mailed out to parents and guardians of area elementary and high school students whose immunization records were not up to date.
The health unit said it is still waiting to hear from about 1,800 families.
A second notice has been sent out. If records aren't updated by March 2, 2020, student face suspension from school as of March 3.
Lambton Public Health says the records include immunizations for diphtheria, tetanus, polio, mumps, rubella, measles, meningitis, whooping cough and chickenpox for children born in 2010 or later.
Parents can update records online at www.lambtonpublichealth.ca , by phone or in person at the health unit at 160 Exmouth St. in Point Edward.
Last March, 325 students were suspended from school due to outdated vaccination information.