Mr. Chair, maybe I'll start with the answer to that question.
I think the first-dose, fast strategy was taken up as a result of the National Advisory Committee on Immunization reviewing existing information on the COVID-19 vaccines, but also a wealth of knowledge —decades of experience—about vaccinology, immunology and how vaccines work. Together with mathematical modelling and other considerations, it meant that there was a consensus amongst chief medical officers of health in the provinces and territories to do this strategy.
I think it has paid off and has contributed to increasing population protection. More and more data is coming out, including from the United Kingdom, which shows that the first dose offers significant protection, particularly for serious outcomes, and that the duration of that protection does last.
We also have Canadian data, from Quebec and British Columbia, that I think will provide the world's first glimpse into just how good that first dose is even beyond the 12-week mark. It has been very encouraging.
If you can imagine, if you're doing mathematical modelling, covering twice as much of the population with an effective first dose provides significant benefit, but that doesn't mean you can forget the second dose. You have to come back fast with that second dose.
On that, I will just clarify that the National Advisory Committee on Immunization said “up to 16 weeks”. As the supplies improve, I think we will see that interval potentially being compressed more. I believe British Columbia has just come up yesterday with a 13-week interval now, given their supply management. I think you will see that interval being more compressed as we go along as well.
Just rest assured to Canadians that first doses do matter and they have worked and have prevented a lot of serious outcomes in Canada already.