Ontario to offer third dose of COVID-19 vaccine to select vulnerable populations

TORONTO -

Ontario will begin offering a third dose of a COVID-19 vaccine to individuals most at risk of serious illness.

On Tuesday, the province released a list of vulnerable populations eligible for the third shot, including transplant recipients, patients with hematological cancers, recipients of an anti-CD20 agent and residents of high-risk settings such as long-term care homes, retirement homes and First Nations elder care lodges.

“A complete two-dose COVID-19 vaccine series provides strong protection against COVID-19 infection and severe outcomes, including against the Delta variant, in the general population,” officials said in document released ahead of the announcement.

“However, for some populations, a third dose may be required to provide sufficient protection based on a suboptimal or waning immune response to vaccines and increased risk of COVID-19 infection.”

In July, CTV News Toronto spoke with a 49-year-old kidney transplant patient who said his body developed no antibodies against the virus due to medication he takes.

“My results came back and showed that I didn't have any antibodies at all,” Keith McArthur said at the time. “There have been studies that have show that a third dose won't help everybody in my situation, but it does help at least some people.”

One such study was released the following month, showing that a vaccine booster could be “very effective” in transplant patients.

“We know that transplant patients are immunocompromised and they don’t respond to two doses of the standard COVID vaccine,” co-author of the study and director of transplant infectious disease at the University Health Network Dr. Deepali Kumar told CTV News in August.

“So we decided to do a trial where we looked at a third dose of COVID vaccine to see if we could boost immunity.”

• READ MORE: Third COVID-19 vaccine dose effective in transplant recipients, study finds

In the announcement on Tuesday, Ontario officials said that transplant recipients, patients with hematological cancers, and recipients of an anti-CD20 agent will be contacted by their health-care provider, specialist or hospital program if they are eligible for a third dose. These individuals must wait a minimum of eight weeks after their second dose to get the final shot.

Third doses will be offered to individuals in long-term care a minimum five months after their second doses. According to provincial officials, the immune response in long-term care residents who are fully vaccinated “wanes significantly compared to the general population” after about four months.

The timing of third doses will vary between public health units, officials added, with some beginning as early as this week.

The announcement was made as the government revealed their new vaccination policies for high-risk settings.

• READ MORE: Ontario pauses further reopening as it reveals new vaccine policies

As of Sept. 7, all employees, staff, contractors, students, volunteers and ambulance services at hospitals and in home and community care services will be required to show proof of vaccination or a medical reason for not being vaccinated.

All individuals who do not provide proof of full vaccination with both doses will have to take regular antigen COVID-19 tests. They will also be required to complete an educational session.

A similar testing policy is expected be implemented in publicly funded and private schools across Ontario, as well as licensed child-care centres, although no start date was given.