 | Saturday, September 04, 2021 |
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Good morning! Here's our second look at the week, with a round-up of health and medical science news. If you haven’t subscribed yet, you can do that by clicking here. | | |
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This week: |  | Why rushing COVID-19 booster shots for everyone could do more harm than good |
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| | From mu to C.1.2, here are the latest coronavirus variants scientists are watching closely |
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| | Western provinces driving Canada's 4th COVID-19 wave as physicians warn cases 'out of control' |
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 | A man takes a selfie while receiving the third Pfizer-BioNTech COVID-19 vaccine from medical staff at a coronavirus vaccination centre in Ramat Gan, Israel, on Aug. 30. Israel is urging those over age 12 to get a booster shot, but experts say there isn't data to support rolling out boosters to the general population. (Oded Balilty/The Associated Press) | | Why rushing COVID-19 booster shots for everyone could do more harm than good
Canada should help vaccinate world first and wait for doses that target variants, say experts |
Adam Miller
| | Canadians may be eager to get a third dose of COVID-19 vaccine to further protect themselves in the fourth wave, but the lack of evidence for booster shots in the general public and the desperate need for vaccines worldwide should give us pause.
The World Health Organization recently called for a moratorium on boosters until at least the end of September, but rich countries are forging ahead with plans for additional doses now regardless — including parts of Canada.
Israel has made third doses of COVID-19 available to everyone aged 30 or older, while the U.S. plans to offer boosters to anyone eight months out from their second shot on Sept. 20.
Other wealthy nations with ample vaccine supply have taken a slightly more nuanced approach, with France, Germany and the U.K. announcing third doses only for vulnerable populations at heightened risk of declining COVID-19 immunity.
But the European Centre for Disease Prevention and Control (ECDC) health agency said Wednesday there is no need to rush out booster shots for the general public because all authorized vaccines are highly protective against hospitalization, severe disease and death from COVID-19.
Now, with more than 67 per cent of our total population fully vaccinated, the question of whether Canada should be giving third doses to everyone eligible to better protect against delta is on the table as other wealthy nations begin to roll out boosters to the general public.
Do Canadians need boosters now?
Canada's National Advisory Committee on Immunization (NACI) is currently weighing the available data on the benefits of booster shots, and is expected to issue guidance soon. But Ontario and Alberta have already begun rolling them out to the immunocompromised.
"There are categories of people that don't make a great response to the vaccine," said Dr. Zain Chagla, an infectious diseases physician at St. Joseph's Healthcare Hamilton and an associate professor at McMaster University.
"Those at the extremes of elderly age, those who have major immunocompromising conditions, where absolutely a booster right now probably makes sense."
Canadian researchers at the University Health Network (UHN) in Toronto recently published a correspondence in the New England Journal of Medicine that showed evidence of "significantly higher immunogenicity" in transplant patients after a third dose.
And a recent preprint study, which has not been peer reviewed, from the Lunenfeld-Tanenbaum Research Institute at Sinai Health in Toronto analyzed 119 Ontario long-term care residents and 78 staff over four months, found much lower levels of neutralizing antibodies in the elderly patients — suggesting a possible need for a third dose in that group as well.
"But then it turns into — what do you do with the general population when studies have suggested that there is still significant protection?" Chagla said.
"There really hasn't been any data suggesting that getting a booster is really going to change their clinical picture."
Delta-specific booster 'better' for Canadians
As other countries rush to roll out third doses to the general public despite a lack of concrete, long-term data — experts say it may be more advantageous to wait for the development of a delta-specific booster to directly target the variant.
Both Moderna and Pfizer-BioNTech are currently working on updated mRNA vaccines specifically tailored to emerging variants, but the third doses that are being rolled out in wealthy nations now are essentially additional shots of the original vaccine formulation.
But the development, testing and approval of a new shot will take time — something not all experts agree we have.
Dr. Anthony Fauci, director of the U.S. National Institute for Allergy and Infectious Diseases, said Friday that three doses of the COVID-19 vaccines are likely needed for full protection, citing two Israeli preprint studies that showed a 10-fold decrease in serious illness for those over 60 and a marked reduction in the odds of testing positive after three shots.
But the data are limited in scope and experts point to the greater need for delta-specific booster shots for the general population, as opposed to third shots of the same formulation, in order to target the devastating variant.
Dr. Allison McGeer, a medical microbiologist and infectious disease specialist at Toronto's Mount Sinai Hospital, says there are two core reasons why developing a booster that specifically targets delta would be advantageous.
"One is it gives you better antibody levels against delta," she said, which could provide better protection against initial infection and onward transmission from the variant.
The second involves something called "imprinting," where your first experience with a virus or vaccine determines the nature of your immune system's response.
"If we're going to have delta as the new big thing, and your immune system is initially responding to [the original strain], then that would not be ideal," she said.
"It might be better to — particularly for kids — vaccinate them against delta."
|  | Black Creek Community Health volunteer Jasleen Kambo, 18, gets her first dose of the Moderna COVID-19 vaccine at a clinic run by Humber River Hospital at the Yorkgate Mall, in Toronto, on Apr. 14. (Evan Mitsui) | Alyson Kelvin, an assistant professor at Dalhousie University and virologist at the Canadian Center for Vaccinology and the Vaccine and Infectious Disease Organization in Saskatoon, says it's also more advantageous to wait until antibodies begin to fall before providing an additional dose — so rushing boosters now may not make sense.
"I don't think there's data to support, in healthy adults, that there is going to be a substantial beneficial effect. You might see a rise in antibodies, but also your antibodies might be at their limit already — so a boost might not do anything," she said. "Timing is important."
Until we have more comprehensive real-world data, experts say if Canada is going to roll out boosters than we should start — and stop — with immunocompromised groups and the elderly for now.
"If the question is asked today, do we all need booster shots? The answer is no, we don't," said Dr. Isaac Bogoch, an infectious diseases physician at Toronto General Hospital and a member of Ontario's COVID-19 vaccine task force.
Future variants pose unseen threat
Without a doubt, the emergence of highly contagious coronavirus variants has been one of the biggest challenges to ending the pandemic in Canada and around the world.
New variants have repeatedly surfaced throughout the pandemic in populations with low vaccine coverage that have been hit hard by unchecked COVID-19 transmission — including India, South America and Africa.
The devastation caused by the original strain of the virus from Wuhan, China was overtaken by the emergence of the highly contagious alpha and beta variants in late 2020, which drove Canada's brutal third wave and set off a mad rush to get people vaccinated.
In the spring, Canada became one of the only countries in the world with significant outbreaks of three different variants occurring at the same time, turning us into a giant experiment on the world stage.
But the delta variant completely changed the battlefield, quickly usurping all other variants to become the dominant strain in Canada by the summer and fuelling a worsening fourth wave at a time when many thought the pandemic would be winding down.
Experts say the shortsighted approach of providing third doses to everyone, based largely on preliminary data and unproven fears over the severity of breakthrough infections, fails to see the bigger picture of what's driving the emergence of variants in the first place: nearly half the planet with no vaccines.
"Allowing 3.5 billion people to remain unvaccinated is a recipe for unmitigated disaster because worse and worse variants will emerge — not to speak of the millions of people who will die," said Dr. Madhukar Pai, a professor of epidemiology and global health at McGill University in Montreal.
"It just completely boggles my mind why world leaders, especially those who can and could have done something, have chosen to allow this inequity to continue."
To put it in perspective, just 1.8 per cent of people in low-income countries have received at least one dose of a COVID-19 vaccine, compared to more than 50 per cent of those in wealthy countries.
Pai, who co-authored a correspondence in the journal Nature with Chagla this week on the need to vaccinate the developing world, says ramping up efforts to vaccinate the world to prevent the emergence of new variants altogether should be a global priority.
"We're now in a fourth wave because of delta. There is no way to prevent worse variants from not only emerging, but also coming into our countries," he said. He wants to see wealthy nations immediately band together, donate vaccines and fund global manufacturing.
"Because if we don't do it, we are in this forever."
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 | A health-care worker administers the Johnson & Johnson COVID-19 vaccine to a woman in Johannesburg on Aug. 20. Scientists in that country first detected a new C.1.2 variant there in May. (Sumaya Hisham/Reuters) | | From mu to C.1.2, here are the latest coronavirus variants scientists are watching closely | | Scientists have warned the coronavirus will keep evolving as it spreads around the world, and there are now multiple new variants being watched closely by global research teams.
One of those, B.1.621, also known as mu, has been dubbed the latest variant of interest by the World Health Organization (WHO). Another, C.1.2, is the subject of headline-making new research exploring how it behaves. Other variants are likely waiting in the wings, yet to be detected.
So why do these new variants matter, what are they capable of, and how much should Canadians care?
Right now, the highly-contagious delta variant — deemed a variant of concern by the WHO back in May — is dominating Canada's COVID-19 cases, making up more than 90 per cent of reported recent infections according to federal data.
But that doesn't mean other emerging variants don't warrant close observation.
"Looking at this virus, it's obvious that we will have new variants," said Alyson Kelvin, a virologist at the Vaccine and Infectious Disease Organization (VIDO) at the University of Saskatchewan.
"What we need to do is to be ready for identifying cases … as well as other variants that are inevitably going to start emerging around the world."
Read more from CBC Health's Lauren Pelley and Adam Miller on what Canadians need to know about the latest variants scientists are watching closely.
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 | COVID-19 and the delta variant didn't deter more than 33,000 Saskatchewan Roughriders fans from packing Mosaic Stadium in Regina on Aug. 6 for a game against the B.C. Lions. Public health measures remain lifted while cases are spiking in the province. (Kayle Neis/The Canadian Press) | | Western provinces driving Canada's 4th COVID-19 wave as physicians warn cases 'out of control' | | Canada's western provinces are largely driving the country's fourth wave of COVID-19 cases, and physicians are now raising the alarm — saying lax and late public health measures helped spark a rise in serious infections that's already putting pressure on hospitals and impacting patient care.
In British Columbia, Alberta and Saskatchewan, infection rates are high above the country's average and far beyond every province to the east, including Ontario, whose population is larger than all three westernmost provinces combined.
The rate of cases in the last seven days in B.C. was 93 per 100,000 people as of Aug. 30, federal data shows, with Alberta's rate at 159 and Saskatchewan's at 135 — with no province to the east hitting more than 43.
In terms of raw case growth, Alberta currently has the most new infections in the country, with more than 7,000 cases reported in one week.
The province is now in the early stages of postponing surgeries and transferring patients to help boost capacity, but it has yet to reinstate major public health measures or bring in a vaccine mandate to curb case growth as the fast-spreading delta variant surges across much of the country.
Read more from CBC Health's Lauren Pelley on the surge in COVID-19 cases in Canada's western provinces. | | | |
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Elsewhere from CBC: | | Chief public health officer says Canada could see 15,000 cases daily by October if vaccinations don't increase | CBC Politics |
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| | Vaccine Hunters is winding down. But they'll be back if you need them, says founder | The Current |
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| | Israel was down to a handful of daily COVID cases. Now it's around 11,000. What happened? | CBC World |
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Cross-Canada health news: | | Reports of assault, verbal abuse as thousands protest vaccine passports outside hospitals across B.C. | CBC British Columbia |
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| | COVID-19 vaccination rate must rise above 85% to avoid fall lockdown, Ontario modelling shows | CBC Toronto |
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| | Amazon Canada adds health disclaimer to searches for ivermectin | CBC Calgary |
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 | White Coat, Black Art | Dr. Brian Goldman takes listeners through the swinging doors of hospitals and doctors' offices, behind the curtain where the gurney lies. |
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|  | Alyssa Smyth and her mother, Cathy, both have long-COVID. (Brian Goldman/CBC) |
Parents of kids with long-COVID warn that children can develop severe symptoms
Dr. Anu Wadhwa says COVID-19 symptoms can start out mild but then become chronic, debilitating | | Parents whose children have developed long-haul cases of COVID-19 are urging others not to underestimate the virus's impact on kids as they prepare for the return to class this week.
Doctors and other health-care workers who treat kids with long-COVID are also calling for more attention to the risks faced by the under-12 set, who can't yet be vaccinated while the delta variant fuels a fourth wave of the pandemic.
They say that even seemingly mild cases of COVID can lead to prolonged illness in kids, despite the predominant message heard throughout the pandemic that children are only modestly affected.
Dr. Anu Wadhwa, a pediatric infectious diseases staff physician at the Hospital for Sick Children in Toronto who has been treating and studying children with long-COVID, says the virus can set kids back for months.
"Most of the children we're following had pretty mild disease that pretty much resolved the way you expected it to," Wadhwa told White Coat, Black Art host Dr. Brian Goldman.
"However, either certain symptoms lingered and persisted or [the kids] had a period of feeling well — and went bike riding for a day or two — and then started to feel worse again," said Wadhwa, who is also an associate professor of pediatrics at the University of Toronto.
"So it seems very typical that even with mild infection, some of these kids are getting very pronounced, persistent symptoms."
Those symptoms include things like joint pain, fatigue, shortness of breath and — perhaps most difficult to treat — brain fog.
White Coat Black Art with Dr. Brian Goldman
Sept. 4 & 5 on CBC Radio One | |
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 | The Dose | The Dose is a weekly look at the health news that matters to you. |
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 | Some provinces and municipalities have brought back mandatory masking in indoor public spaces with the rise in COVID-19 case numbers across Western Canada. (Tyson Koschik/CBC) |
Cases are rising across western Canada. Does that mean the return of COVID-19 lockdowns this fall?
Saskatchewan epidemiologist says a regional response to COVID-19 flare-ups is more likely
As kids head back to classrooms and some companies look at bringing employees back into offices, the delta-driven fourth wave of the pandemic has continued to grow, with case numbers rising sharply across western Canada.
In some areas, they've reached levels that prompted public-health restrictions during the second and third wave, raising the question of whether fall will bring yet another lockdown or set of stringent public health measures across the country.
But Canada's vaccination rate means this fall is different from fall of 2020, says Nazeem Muhajarine, professor of community health and epidemiology in the College of Medicine at the University of Saskatchewan in Saskatoon.
"I don't think that we would be hurrying to issue a stay-at-home order in our provinces," Muhajarine told Dr. Brian Goldman, host of The Dose.
Instead, Muhajarine anticipates a more focused strategy for public health measures this fall, including a regional approach to mandatory mask wearing, social distancing, and proof-of-vaccination documents in areas where COVID-19 numbers are high.
"I think we will address the flare-ups that are happening in particular places as needed," he said.
"We have to have these measures happening where the background COVID prevalence or COVID rates are higher than in other places."
However, as cases rise, some are concerned that those focused measures won't happen fast enough to keep schools and workplaces safe and avoid overwhelming the health-care system.
Listen to The Dose for free on CBC Listen or on your favourite podcast app — including Apple Podcasts and Google Podcasts.
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Trending studies from around the world: | | Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID Symptom Study app | The Lancet |
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| | Underlying Medical Conditions and Severe Illness Among 540,667 Adults Hospitalized With COVID-19, March 2020–March 2021 | CDC |
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| | Durability of antibody response to vaccination and surrogate neutralization of emerging variants based on SARS-CoV-2 exposure history | Scientific Reports |
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Stories we found interesting this week: | | The debate over Covid-19 vaccine boosters, what to call them, and whether they’re needed | STAT |
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| | | The ivermectin mess: People are embracing a dangerous livestock drug, while rejecting vaccines | The Globe and Mail |
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| | Thanks for reading! You can email us any time at secondopinion@cbc.ca with your comments, questions, thoughts or ideas. | |
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