It's not different in Ontario. The "attaining 16 years of age" you read in the Health Care Consent act is in regard to people being admitted to a care facility and not in regard to people receiving treatment.
For just treatment there is no legal minimum age for consent in Ontario.
"Treatment’ in the HCCA includes anything done for a therapeutic, preventive,
palliative, diagnostic, cosmetic or other health-related purpose, and therefore
includes vaccination"
"There is no age of consent for treatment in Ontario. All persons in Ontario who have decision-making capacity have the right to make decisions about vaccination,
including 12-17 year-olds."
It is legal. We have something called "Mature Minor Consent".
https://www.healthlinkbc.ca/healthlinkbc-files/infants-act-mature-minor-consent-and-immunization
It's not different in Ontario. The "attaining 16 years of age" you read in the Health Care Consent act is in regard to people being admitted to a care facility and not in regard to people receiving treatment.
For just treatment there is no legal minimum age for consent in Ontario.
https://jcb.utoronto.ca/wp-content/uploads/2021/05/Bioethics-Table-Brief-Vaccinating-Ontarians-Aged-12-17-Legal-and-Ethical-Requirements.pdf
Here are the requirement to give consent to a treatment according to the HCCA:
https://imgur.com/SfbBV0P.png
No mention of age.
The "16 years" is a limit for giving consent on incapable person's behalf:
https://imgur.com/ZUuUQy2.png