Only nine Ontarians under the age of 60 have ended up in the ICU with a breakthrough case of COVID-19

Will vaccine mandates be extended to kids 5-11? Ontario's chief medical officer casts doubt on whether proof of COVID-19 vaccination requirement will be extended to kids aged five to 11.

TORONTO — There have been more than 17,000 so-called breakthrough cases of COVID-19 involving fully vaccinated Ontarians over the last year but the number of those people under 60 who eventually ended up in an intensive care unit is only nine.

Public Health Ontario has compiled a new report examining the prevalence of breakthrough infections in the province up until Nov. 14.

The report provides the most exhaustive look at breakthrough infections in Ontario to date and seems to support the testimony of public health experts, who have consistently argued that the vaccines are extremely effective at preventing both symptomatic infection and hospitalizations.

The data shows that there have been 17,596 breakthrough cases among the more than 11 million Ontarians who are fully vaccinated, accounting for 3.8 per cent of all lab-confirmed cases.

But it also suggests that the share of fully vaccinated people who end up in hospital is even lower, particularly among those under the age of 60.

In fact, over the last year there have been just 83 people under the age of 60 who have ended up in hospital with a breakthrough case of COVID-19. Of those individuals, just nine of them have required treatment in an intensive care unit.

As a point of comparison a total of 8,355 unvaccinated individuals under the age of 60 have ended up in hospital with COVID-19 over the same time-period and 1,722 of them have required treatment in the ICU.

Across all age groups the number of individuals with breakthrough infections who ended up in intensive care is 81, accounting for about 1.9 per cent of COVID-19 ICU admissions.

The release of the data comes as fully vaccinated individuals begin to account for an increasingly larger share of Ontario’s overall caseload, sometimes even making up the majority of new infections in the province’s daily case counts.

But the authors of the report caution that an increasing share of breakthrough infections is to be expected with more than 85 per cent of Ontarians age 12 and up now fully vaccinated.

They do say that the evidence continues to suggest that when COVID-19 cases occur following vaccination “there is evidence that vaccines reduce symptomatic infection, the severity of illness, as well as transmission.”

“Over time as a population becomes more highly vaccinated the number of post-vaccination cases, including breakthrough cases, will likely increase,” the report notes. “Even with a highly effective vaccine, cases may occur among vaccinated individuals due to a larger proportion of the population being vaccinated than unvaccinated.”

The data released by Public Health Ontario suggests that the rate of COVID-19 infections in fully vaccinated individuals has “remained consistent over time,” even with many of those people now months removed from receiving their second doses and Ontario beginning to administer booster shots to a small group of individuals amid concerns about waning immunity.

However, infectious disease specialist Dr. Isaac Bogoch told CP24 on Thursday morning that it also points to the need for a wider rollout of third doses.

So far there have only been 40 instances of breakthrough cases of COVID-19 involving individuals who are 14 days out from a third dose.

“If we look at the data it is pretty clear that we could expand or should expand eligibility for third doses,” he said. “We don’t all need third doses and we can debate which age cohort would be best served by third doses at this time but my take is the 50 and up crowd. Other people might look at the data and say something else. That is OK. But I think it is fair to say that we should be expanding third doses in Ontario.”