The chair of the largest school board in the country is asking the Ontario government to add COVID-19 vaccines to the list of compulsory immunizations for eligible students.

In a letter posted to the Toronto District School Board website Friday, Alexander Brown said putting COVID-19 vaccines on the list would not only further protect students, staff and their families against the virus but also will allow schools to remain open amid the fourth wave.

"As you know, medical professionals and government officials in our city, province and country continue to advise the public that vaccinations are our greatest defence against COVID-19 and that being fully vaccinated significantly reduces the risks of the most serious outcomes of COVID-19, including the variants of concern to date," Brown wrote in the letter.

It is addressed to Education Minister Stephen Lecce, Ontario Chief Medical Officer of Health Dr. Kieran Moore, and Toronto's medical officer of health, Dr. Eileen de Villa.

"We hope that you highly consider our request as the new school year fast approaches and majority of our students are returning to in-person learning," Brown added.

In Ontario, children attending primary and secondary schools are required to be immunized against nine diseases -- diphtheria, tetanus, polio, measles, mumps rubella, meningitis, whooping cough and chickenpox under the Immunization of School Pupils Act.

When asked about the letter, a spokesperson for the Minister of Health did not say whether they would consider adding the COVID-19 vaccine to the mandatory list but said that the reporting and assessment components of the act are already being met through other systems.

"The province will work with trusted public health units to use the existing COVaxON system to safely and securely confirm the vaccination status of students. The province is committed to keeping parents informed about how their child's COVID-19 vaccine information and enrollment data is being used to keep schools safe," the spokesperson said.

"This will equip local public health units with the information they need to ensure rapid case and contact management if required to limit disruptions in the event of cases or outbreaks and keep kids in class."

The Ontario government said they have asked all public health units and school boards to host vaccine clinics in or near schools to increase uptake.

The think tank People for Education made the same request last month. The group sent a letter to Lecce and Health Minister Christine Elliott, asking them to add COVID-19 to the list of diseases for which vaccination is already mandated.

According to provincial data, those 12-17 continue to lag behind other age groups in vaccination coverage, with only 63.7 per cent double dosed.

Last week, TDSB trustees voted in favour of making vaccines mandatory for staff, trustees and visitors.

Classes will begin at TDSB schools on Sept. 9.