As research suggests that COVID-19 has infected roughly half of the Canadian population, the emergence of an even more contagious version of the virus means some people may be in for another round.
But questions remain about the prevalence of reinfection, and the short and long-term health impact that subsequent cases of the virus could have.
With cases on the rise, here’s what the experts had to say about the emerging evidence of reinfections.
The emergence of the Omicron variant ushered in a tsunami of infections that saw the proportion of the population with antibodies to the virus rise from seven per cent to 45 per cent between December 2021 and May 2022, according to an analysis published by Canada’s COVID-19 Immunity Task Force this month.
The task force’s co-chair, Catherine Hankins, said the jury is still out on how likely it is that this previously infected population will catch the virus again, particularly as the BA.5 subvariant of Omicron fuels a summer surge.
“All we know is that it can happen,” said Hankins, a professor at McGill University. “This particular variant is really capable of evading immunity, including immunity to its previous … subvariant.”
Prabhat Jha, a professor of epidemiology at the University of Toronto’s Dalla Lana School of Public Health, said early hopes that Omicron would act as a “benign natural booster,” spreading rapidly but causing only mild symptoms, did not bear out.
“As more evidence accumulates, it suggests that Omicron isn’t the great protector that we all thought it would be,” he said, citing data from the U.K.
2:05 BA.5 variant soon to be dominant in Saskatchewan, deputy CMHO says
BA.5 variant soon to be dominant in Saskatchewan, deputy CMHO says
Lynora Saxinger, a professor with the University of Alberta’s department of medicine, said BA.5 is different enough from previous strains that the immunity built up by a case of an earlier variant may not prevent infection.
“It’s not impossible to get reinfected,” she said.
How much protection do you get from “hybrid immunity”?
People who have been both vaccinated and infected should be bolstered by “hybrid immunity,” said Hankins. But signs that some people are getting reinfected with COVID-19 not long after a previous bout indicates that any natural immune boost would be short-lived, she said.
“People really shouldn’t think it’s done and dusted. They get it, and that’s it,” Hankins said. “You’re going to get it again if you keep exposing yourself.”
Saxinger said that BA.5 may be even more adept at breaking through hybrid protection, but at this point, it’s uncommon for people who have had Omicron to be reinfected by one of its relatives.
“The combination of vaccination plus relatively recent-ish infection? is not terrible against (BA.4 or BA.5,) especially if you don’t have any risk factors.”
Canadian studies have shown that people with three COVID-19 vaccines and one infection have the highest level of antibodies, Jha said.
Still, he emphasized that people who have been infected can benefit from another COVID-19 shot.
“The evidence does very clearly say that counting on a natural infection to protect you is really risky. We knew that from the start,” he said. “The best protection is at least three doses of the vaccine.”
How does reinfection affect the severity of illness?
Hankins said it’s difficult to track whether people, on average, get sicker the second or third time catching COVID-19.
“It seems to vary a lot by people,” she said. “The general expectation would be that you wouldn’t be as sick the second time around, but we’re seeing everything.”
While governments report a high number of people in hospital _ some of whom have had the virus before _ may seem to suggest that reinfection leads to more serious illness, Saxinger said, that’s not necessarily the case. It’s just that there are more cases of COVID overall.
“It’s really a function of just the sheer volume of transmission where we start to see increases in severe outcomes,” she said. “But on a per person level, the risk of severe outcome still seems to be quite low, especially if you’ve had a combination of being fully vaccinated, and also previously infected.”
Jha said this is another area where more study is needed.
“But in theory, I have no doubt that having multiple infections isn’t good for you,” he said.
“Some cavalier people say, `I’m just going to get infected a few times, and then I’ll be fine,”’ he added.
It’s also unclear, he said, whether reinfection increases that likelihood of contracting long COVID.
“There is a suggestion that multiple infections can contribute to longer symptoms. But again, this is something we don’t know enough about.”
1:45 Emergency room doctors urge people to get 4th COVID-19 vaccine dose amid 7th wave
Emergency room doctors urge people to get 4th COVID-19 vaccine dose amid 7th wave
What should we do?
“Everyone wants a quick answer and says, `Okay, I want to know what to do. And I want to get this behind me,”’ Jha said. “But the virus works on its own timetable.”
“Our immune system is trying to keep up with a mutating virus … And we have to basically be sensible.”
Increasing third-dose uptake is key to protecting people from reinfections, he said. Each shot you receive reduces the severity of disease.
National data shows only 56 per cent of Canadians 12 and older have at least three doses of a COVID-19 vaccine, compared to roughly 90 per cent who have two doses.
Hankins agreed that getting a third shot is crucial.
“This is a highly infectious agent, but the more immunity you have on board, the better it is,” she said.
The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.
It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.
Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”
Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.
Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.
A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.
On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.
Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”
But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”
“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.
Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.
Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.
Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.
“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.
“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”
This report by The Canadian Press was first published Sept. 13, 2024.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.
The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.
Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.
“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”
The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.
A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.
Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.
“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.
Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.
The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.
“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.
This report by The Canadian Press was first published Sept. 11, 2024.
ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.
Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.
Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.
Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.
The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.
“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.
Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.
Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.
Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.
A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.
This report by The Canadian Press was first published Sept. 10, 2024.
