As COVID-19 cases rise in parts of the country, experts expect the number of infections among fully vaccinated people to increase. But that doesn’t mean that vaccines have stopped working.
Experts say cases among fully vaccinated individuals — called breakthrough infections if they occur at least two weeks after a second dose — are rare, even against the more transmissible Delta type of virus.
They add that a fully vaccinated person is less likely to become seriously ill or die after contracting a COVID-19 infection.
“So far, vaccines do exactly what we expect them to do,” said Dr. Isaac Bogosh, an infectious disease physician at the University of Toronto.
“It lowers the risk of people getting infected, it dramatically reduces the risk of people getting very sick and going to hospital, and there’s also good growing data showing that vaccines reduce the degree to which someone gets infected.”
So what do we know about paranormal injuries? The Canadian Press Bogoch and other health experts were asked to break the flag.
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How often do breaches occur?
In the United States, new data published by the Centers for Disease Control and Prevention (CDC) shows that about a quarter of coronavirus infections among Los Angeles County residents were among individuals who were fully vaccinated between May and late July — the period when the delta variant is severe. The infection was common.
This type of data indicates what Canada can expect as well.
Data from Public Health Ontario showed that known superbug infections accounted for less than one percent of all COVID-19 cases reported in the province from December 14, 2020 to August 7, 2021. But as the proportion of Canadians vaccinated increases, so will the number of people who Those exposed to delta disease were vaccinated. Experts say we will likely see more hacks.
However, those who didn’t get shots were still more at risk. Public Health Ontario data found that unvaccinated individuals were about eight times more likely to contract COVID-19 over the past 30 days.
Recent cases in British Columbia showed an infection rate 10 times higher among unvaccinated people and a 17 times hospitalization rate.
Somon Chakrabarti, an infectious disease physician in Mississauga, Ont. Although Delta is a problem, vaccines still provide excellent protection.
“There are a lot of deltas right now, so we see people who get COVID after they get vaccinated — but they get mild disease almost uniformly,” he said.
“Over time, we’ll see more (breakouts) because we’re looking for it…but you have to compare it to the massive number of fully vaccinated people who are exposed to COVID and not[get infected with it].”
A British study in July suggested the vaccine’s efficacy is lower against the delta than the alpha variant, providing protection against infection by 67 to 88 percent. But the effectiveness against death and severe disease remained high.
Who is most likely to get serious infections?
Although this does not happen often, some people who were fully vaccinated have either required hospitalization or intensive care or died after contracting the infection.
According to the latest CDC study of infection in Los Angeles County, only 3.2 percent of fully vaccinated individuals who contracted the virus were hospitalized, only 0.5 percent were admitted to the intensive care unit, and 0.25 were placed in cent on a ventilator. .
Bogoch said emerging global data suggests that those with severe breakthrough outcomes likely have other risk factors for developing serious illness.
“These are usually very old, frail or immunocompromised individuals,” he said. “And these are the people who will not have the same degree of immune response to the vaccination compared to the younger cohorts.”
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Since these segments of the population were also among the first vaccination priorities when vaccination began in Canada in December, some experts say weakened immunity may be having an effect in certain groups.
A preprint study from McMaster University immunologists suggests that those receiving long-term care may soon need a booster dose to amplify their protection.
“In the general population, we are not thought to have reached that diminished immunity,” said Don Bowdish, a co-author of the preprint study, which is currently under review.
“In long-term care and in the vulnerable, yes, they do reach diminished immunity, but they never have long-lasting immune responses.”
Most studies on immune longevity look at antibody levels over time, Chakrabarti said. But while the antibodies decline, the T-cell responses linger much longer to go on to fight severe infections.
“Antibodies are like a brick wall,” he said. “They are powerful but with enough force you can knock them down.” “But the kind of long-term immunity you have with T cells, it’s like a concrete wall. That’s not something that falls easily.”
Could a superinfection lead to further transmission?
Recent data from the UK has shown that some fully vaccinated COVID-19 patients have similar viral loads to unvaccinated people who have contracted the virus.
While this may indicate that vaccinated people are completely contagious, experts say that is not the case.
More studies have suggested that viral load drops faster in fully vaccinated people than in those who haven’t been vaccinated, Bowdish said. “So you may have one day of infection versus five,” she explains.
“Right now, we see that delta is as contagious as chickenpox in people who are not immunized,” Bowdish said. “In people who have been vaccinated, it will probably be more like influenza…so for someone who has been fully vaccinated, there is still potential for transmission, but it will be much lower.”
Bowdish added that the amount of viral load a person carries does not necessarily translate into how infected a person is.
She noted that studies conducted during the first wave, before the emergence of the Delta, indicated that children carried large amounts of viruses but were not as infectious as adults. She said the presence of symptoms and the behavior of the host – are they sneezing and surrounded by people? Transmission of the effect is more than the viral load itself.
Chakrabarti added that viral load does not always indicate the presence of a live virus, and since vaccinated people likely won’t have symptoms, they also likely won’t become super spreaders.
How do we stop penetration in cases?
Some experts believe the COVID-19 virus will become endemic, with small seasonal waves continuing to pass through mostly unprotected populations.
This means that it will be difficult to stop a penetrating infection completely.
The best way to stop the spread of disease between vaccinated and unvaccinated groups, Bogoch said, is to continue adding layers of protection, including wearing masks and restrictions on indoor gatherings, to “stop infection in the community.”
“Right now, we have to vaccinate, as well as simultaneously implement other mitigation efforts,” he said. “We’re going to get out of this pandemic. We’re not there yet.”
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