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What we know so far about getting COVID-19 twice in the age of Omicron – Yahoo News Canada

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A close-up look at the Omicron variant of SARS-CoV-2. It’s more transmissible and more likely to lead to reinfection than earlier strains of the coronavirus. (HKUMed and Electron Microscope Unit/HKU – image credit)

Getting COVID-19 a second time was once considered a rarity. Now, with the more transmissible Omicron subvariant BA.2 spreading throughout the country, reinfections are becoming more common, immunology and infectious diseases experts say.

Exactly how common is not clear. Testing is limited across the country and detailed COVID-19 data that’s publicly available is also limited.

“There is a dearth of testing that’s happening and there’s some information coming out to suggest that the rapid antigen tests are not as accurate as we hoped against Omicron,” said Jennifer Gommerman, professor of immunology at the University of Toronto, and the Canada Research Chair in tissue specific immunity.

Prevalence is a difficult question to answer, but we know that there’s lots of virus going around.”

PCR test-positivity rates, hospitalization figures, and wastewater data in many provinces are showing increased transmission of the virus.

And data from around the world do show reinfection risk is higher with Omicron, experts say.

“When we think about this idea of reinfection, we have to appreciate we are still facing a virus that has a unique ability to circumvent those early defences from neutralizing antibodies,” said Jason Kindrachuk, a virologist and assistant professor in medical microbiology and infectious diseases at the University of Manitoba in Winnipeg.

Yet, reinfection cases largely do not cause worse symptoms of the disease, said Kindrachuk, who is also the Canada Research Chair in the molecular pathogenesis of emerging viruses.

There are many factors as to why someone may be reinfected with the virus, and researchers are trying to get a better understanding of reinfections and what it means during Omicron.

Jeff McIntosh/The Canadian Press

Reinfections rising in global data

Data released by Public Health Ontario last week shows some 11,730 Ontarians have been reinfected with COVID-19 since November 2020.

Reinfection, according to Ontario health officials, is when someone has had two lab-confirmed cases of SARS-CoV-2 with evidence that these were “separate infections caused by different viral lineages.”

South African scientists had warned in December that reinfections among people who’ve already battled COVID-19 appeared to be more likely with Omicron than with earlier coronavirus mutants.

A recent rise in reinfections has been seen in parts of the world like the United Kingdom, which had a similar vaccine rollout to Canada.

Before Dec. 6, the proportion of daily cases in England thought to be reinfections had been below two per cent for nearly six months.

That rate is estimated to have risen to 9.9 per cent as of February, a Reuters analysis of UKHSA data found.

In Italy, a spokesman for the National Institute of Health said in February that reinfection cases stood at around three per cent of all infections, up from around 1.5 per cent before Omicron.

Why does reinfection happen?

There are a lot of factors as to why someone is reinfected with COVID-19, including vaccination status and when a person got a vaccine or infection, said Dr. Lynora Saxinger, an infectious disease specialist at University of Alberta in Edmonton.

A study done in Qatar published in the New England Journal of Medicine last month found recovering from a previous infection was approximately 90 per cent effective at preventing reinfection from the Alpha, Beta and Delta variants.

Protection against reinfection with the Omicron variant was lower at 60 per cent but “still considerable,” said the authors.

Another important aspect of the risk of reinfection is vaccine-induced immunity.

Hannah Beier/Reuters

The strength of immune response will partially depend on a person’s age and overall health. The very old, very young, and immunocompromised will have weakened responses, for example.

That’s why fourth doses are now being rolled out to the more vulnerable populations across the country.

And although vaccines have repeatedly been proven effective in preventing serious illness and hospitalization, Omicron is still “quite good at punching through the equivalent of two doses and in many cases, two doses plus infection or three doses,” said Saxinger.

It’s known that antibodies do drop off over time after someone is vaccinated or infected, said Benoit Barbeau, a professor in the biological science department at Université du Québec à Montréal who studies virology.

“So if you’ve been infected in December or early January, you’d already have less levels of antibodies. It doesn’t mean that you’ve totally lost your protection against infection, but definitely you’ll have less protection than say 10 days after being infected,” he said.

The good news is that the immune response generated through vaccination “is strong enough to keep us from getting really severe disease and ending up in hospital,” said Gommerman.

That’s why experts are recommending people get a booster shot for that added protection.

As for the Omicron subvariant BA.2, early research out of Denmark hints that reinfections with that strain seem rare.

What do we need to learn?

Barbeau said as parts of Canada and other countries deal with a sixth wave, more data will emerge on who is getting reinfected and why.

“There’ll be other variants. The risk of reinfection will always be there,” he said.

But he emphasized that the immunity in the population, whether from vaccines or prior infection, is building up and allowing us to reduce transmission and hospitalization.

All of this is happening as research continues into improving vaccines, whether it’s adapting to new variants or research into new methods to administer vaccines like through the nasal cavity, he said.

“It’s very important to continue improving the vaccines.”

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Canada to donate up to 200,000 vaccine doses to combat mpox outbreaks in Africa

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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.

The Canadian Press. All rights reserved.

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How many Nova Scotians are on the doctor wait-list? Number hit 160,000 in June

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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.

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Newfoundland and Labrador monitoring rise in whooping cough cases: medical officer

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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.

The Canadian Press. All rights reserved.

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