Ottawa Public Health says its annual surveillance of the immunization records of children and youth in elementary and secondary schools has been successful in reducing the number of students without their required vaccines amid an outbreak of measles across the province.
The city’s Interim Medical Officer of Health Dr. Trevor Arnason provided statistics at the Board of Health meeting Monday evening of the health’s unit’s enforcement of the Immunization of School Pupils Act for 7-year-old (born 2017) and 17-year-old (born 2007) students.
Arnason told city councillors that the number of 7-year-olds missing one or more required vaccinations has gone from 70 per cent to 24 per cent this school year.
The number of 17-year-olds without the vaccines required to attend school has reduced from 59 per cent to 34 per cent to date.
Arnason says he expects those numbers to improve further as the process continues through the end of the school year.
“Although we have more work to do to promote vaccination uptake, our efforts are making a difference,” he said.
Children attending school in Ontario are required to be vaccinated against diphtheria, tetanus, pertussis (whooping cough), polio, measles, mumps, rubella and meningococcal disease. Children born after 2010 must also be vaccinated against chicken pox.
The health unit began sending out first notices to children and youth with out-of-date immunizations in December and January to about 15,000 students without their required vaccinations. Children with incomplete immunization records after two notices face a 20-day suspension.
The data comes as Ontario has seen an outbreak of measles cases across the province, with public health officials linking the majority of cases to unvaccinated children.
Arnason said that while Ottawa has not seen any cases of measles to date, OPH continues to monitor the situation.
“OPH continues to monitor all reportable infectious diseases, including measles, to ensure our readiness to respond by working with local health care providers and local hospitals,” Arnason said.
Arnason urged people to get vaccinated if they haven’t already, saying it remains the most effective way to prevent measles, providing close to 100 per cent protection against the illness.
While vaccines are normally administered by primary care doctors, OPH has been providing them for families facing barriers in accessing routine immunizations through its Kids Come First - Vaccinate program and drop-in clinics.
Arnason reported that OPH provided over 26,000 routine childhood immunizations in 2024, including 3,900 for measles. In the first quarter of 2025, the health unit administered 1,500 measles vaccines to children and youth.
Cases have been reported in Ottawa’s neighbouring health units, including in the South East Health Unit (SEHU), which has seen exposures in Kington, Belleville, Picton, Bloomfield and Trenton.
The Renfrew County and District Health Unit has also warned of a possible exposure in the communities of Cobden and Petawawa after two cases were detected aboard an Ontario Northland Bus coming from northern Ontario.
To date, there have been over 815 confirmed cases of measles reported in Ontario from Oct. 18, 2024 to April 9, 2025, including 155 new cases last week, according to Public Health Ontario.
