Who gets sick? Report sheds new light on breakthrough cases and vaccine protection against hospitalization

As Ontario tries to keep a resurgence of COVID-19 cases under control, new data from Public Health Ontario show only nine fully vaccinated people under 60 have ended up in the ICU.

The report paints the most detailed picture yet of breakthrough cases – and who is very ill despite being fully vaccinated – show that the majority of those in need of hospital care are adults over the age of 60, with the highest proportion in the 80s.

Experts say the findings emphasize that vaccines work well to prevent infections and hospitalizations. But they also support opening third doses of the COVID vaccine to older adults, and highlight why masking and other public health measures are still critical at this stage of the pandemic to protect the most vulnerable.

“It’s clear that vaccines work phenomenally well,” said Dr. Isaac Bogoch, an infectious disease specialist and a former member of Ontario’s now disbanded vaccination work force.

“But if you look at all the breakthrough cases, there’s a greater probability that the older cohorts will have more serious infections.” Based on this and data from other parts of the world, “it would make sense to expand the third dose eligibility to the 50-year-old senior cohort and above.”

And Israel, but in Ontario only a few groups are eligible, including health care workers, people 70 and older, people who have received two doses of Astrazeneca or one dose of Johnson & Johnson, and first. Peoples, Inuit and Metis adults. You must be 168 days after your second dose to receive a third dose. Immunocompromised individuals, transplant recipients, patients with hematologic cancers and seniors living in congregational settings, such as long-term care homes, retirement homes and first peoples senior care lodges, are also eligible.

The Public Health Ontario report, which includes Covid vaccination and case data up to November 14, shows that there were only 17,596 breakthrough cases out of the 11.1 million people who underwent two doses of the vaccine. Since November 14, there have been only 40 cases after a third dose, the data show.

“The take-home message is that the COVID-19 vaccines … are highly effective in protecting against infection, and particularly effective in protecting against serious outcomes, including hospitalization and death, of COVID-19,” Dr. Sarah Wilson , A public health doctor in Public Health Ontario, said in an e-mail to the star.

Since Nov. 14, unvaccinated people have made up 91 percent of Covid cases in Ontario, with breakthrough infections accounting for 3.8 percent of cases. Public Health Ontario defines a breakthrough case as “people who received two doses of a COVID-19 vaccine and became infected more than two weeks after receiving their second dose,” Wilson said.

The report noted that a similar trend was observed for COVID hospitals and deaths “with unvaccinated cases accounting for 90.9 per cent of hospitalizations and 90.2 per cent of deaths, while breakthrough cases accounted for 2.7 per cent of hospitals and 3.3 per cent of hospitalizations. Since November 14, 178 fully vaccinated people have died from a covid infection.

Although the data show that older adults are more at risk of being hospitalized for a breakthrough infection – particularly those over the age of 80 – the rate of “hospitalizations was higher among unvaccinated people compared with fully vaccinated people.”

Wilson said the data make it clear that the risk of COVID infection is higher for those who are unvaccinated. For those 60 and older, the risk of being hospitalized with the virus was about 16 times higher for unvaccinated people compared to those who had two doses.

Dr Zain Chagla, an associate professor at McMaster University, said that only nine admissions to the intensive care unit in people under 60 was “pretty remarkable,” but the “opposite side of the coin is that those over 60 probably require booster doses. . “

Especially since the global vaccine supply is still strained and there are people in some countries who still do not have access to first and second doses, “you want to make sure that (third doses) are used in people where they will get the most benefit . ”

Lucy Gerardi, who turns 68 soon, would be first in line if third doses were opened for her age group.

“You just want to have that extra sense of security,” said the retired biology teacher and Oakville resident. Since Tuesday, it has been 168 days since her second shot and she has called public health officials trying to get more information about when she could get a third, without success.

Gerardi said, “You’re just in a limbo.

“But I think we should be grateful that we have at least two shots, when there are people in the world who have none.”

Nearly 420,000 third doses were administered in Ontario, according to the Department of Health spokesperson Bill Campbell, up from 290,000 last week. The numbers will soon be reported publicly. “Ontario’s plan is to gradually expand eligibility for a booster dose to all Atarians over time,” he said in an e-mail statement. Meanwhile, in accordance with the recommendations of the National Advisory Committee on Immunization (NACI), they are offered to vulnerable populations, Campbell added.

Although the Ontario data show that Covid vaccines work very well, they still do not offer complete protection, said Dr.

“The message that is distilled from this report should not be one of nihilism, that vaccines just don’t work well enough,” he said. “The vaccines work very well, but they have their limitations.”

Therefore, it is still crucial to maintain public health measures, particularly masking and minimizing risks that come with crowded, poorly ventilated indoor spaces, even with a highly immunized population, Sharkavi said.

“We need to keep a sense of vigilance around the things that can keep people at risk of becoming ill. And that means preventing the possibility of breakthrough infection by not just relying on the vaccines alone.”

Wilson said Public Health Ontario will publish further reports on breakthrough infections “that could be used to inform third-dose rollout” and that researchers are looking at data on different age groups and the timing of infection after a second dose.