Based on slightly under 90% fully vaccinated in those 16 and above in Ontario (
COVID-19 Tracker Canada - Provincial Vaccination Tracker) that would give a crude vaccine efficacy against hospitalization around 80%. Here is a good graph that shows how as a population becomes more vaccinated even with a highly effective vaccine more vaccinated cases will be seen.
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Given 96% of those over 65 are vaccinated and those with more comorbidities tend to be vaccinated if you match by age and comorbidities you are looking at a vaccine efficacy over 90%. If the vaccinated had the same hospitalization rate as the unvaccinated you would have 4000 extra hospitalizations which is scary.
You brought up a good point on what percentage of those hospitalized are there for another reason besides covid and are the numbers inflated. Mad4vols referenced the breakdown of what percentage of those hospitalized are in the icu. Those requiring icu level care are there because they need a ventilator or alot of oxygen to maintain an oxygen level to keep living or need medicine to keep their blood pressure up. Someone who came in for routine surgery or broke their arm rarely needs icu level care. Those with severe covid do. A third of those unvaccinated are in the icu which fits with other cohorts of those hospitalized with covid symptoms
Outcomes and Mortality Among Adults With COVID-19 at US Medical Centers
So it is unlikely that a huge percentage of those unvaccinated who are hospitalized are there because of other reasons. Of note a tenth of those vaccinated who are hospitalized are in the icu which does raise suspicion that many of those are there because of other reasons. This further would increase vaccine efficacy.