There is still a lot of work to be done to ensure that Ontario residents receive a third dose of the COVID-19 vaccine, says the scientific director of Ontario's COVID-19 Scientific Advisory Table, as discussions begin to intensify around fourth doses.

On the other hand, Dr. Fahad Al-Razzaq told CP24 on Monday that although much of the current talk is about the fourth dose, for me scientifically it clarified the opportunity, the thing we need to do - which is not a question of availability, the vaccine is available to us - is that third dose."

His comments come as opposition parties in Ontario call for expanding fourth doses in the province, as Quebec has done now, ahead of a potential new wave.

Dr. Fahad Al-Razzaq currently recommends third doses in Ontario for all people aged 12 and over, while fourth doses are offered to those aged 60 and over, as well as those aged 18 and over from First Nation or Inuit or Métis.

But according to the latest vaccination data released by the province, only 57 percent of those aged 12 and over have received a third dose, despite it being widely available in the province.

"That third dose, that is the dose that clearly gives you increased protection not only against infection, but from severe illness. Razzaq said, 'Severe illness is what we care about most.' "So there are a lot of people in Ontario now who are eligible for that third dose and have not received it."

Ontario began rolling out third doses in November and expanded eligibility to anyone aged 18 and over in late December.

However, uptake of the third dose was disappointing and Ontario residents were slow to get vaccinated.

While some people indicated they did not want to get more than the originally recommended two doses, Razzaq said advice on how many vaccines are needed has changed as the pandemic progressed and the virus evolved.

 Razzaq said: "The virus has proven to be a terrible opponent for us."

Explaining, "It has mutated to the extent that what is currently circulating in Ontario, Canada and the world is almost unrecognizable compared to what we originally saw and developed vaccines against."

Adding, "And so we have these increasing rounds of vaccination because we are doing our best to protect ourselves from a mutated virus."

Razzaq added that the new vaccines are promising in providing better protection against the latest virus strains.

What happens in the future is truly unclear.

Razzaq said one very promising thing is vaccines that are designed and developed according to what is currently circulating, unlike what was available two years ago when the virus first appeared from China, so there is hope that these new generations of vaccines in particular give us more durable protection." 

Razzaq said that in the meantime, especially with fall approaching when other respiratory illnesses are widespread, it makes sense to get any vaccines you are eligible for and continue considering masking in high-risk places to avoid infection.