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From mu to C.1.2, here are the latest coronavirus variants scientists are watching closely – CBC.ca

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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.

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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.” 

Here’s what Canadians need to know:

What is the B.1.621 — or mu — variant?

B.1.621 is the latest variant of interest, according to the WHO, and was given the designation — and a catchier Greek alphabet-based name, “mu” — on August 30.

“The mu variant has a constellation of mutations that indicate potential properties of immune escape,” reads the WHO’s latest weekly epidemiological update.

That means those with some level of immunity to earlier strains, either by previous infection or vaccination, might be susceptible to infection from mu — but that’s only according to preliminary data and “needs to be confirmed by further studies,” the update continued.

People line up outside a vaccination centre in Melbourne, Australia, in August as the city experiences its sixth lockdown while battling an outbreak of the delta variant of the coronavirus. (William West/AFP/Getty Images)

The variant was first detected in Colombia back in January, and since then, the country has experienced hundreds of cases and the variant has also been reported in 39 other countries around the world.

Here in Canada, it’s barely making a splash: Mu cases have been reported for weeks, but so far, the variant hasn’t made up more than three per cent of cases in any given week and recently totalled just 0.3 per cent — though federal data since mid-July is still accumulating and could change.

What is the C.1.2 variant?

The variant C.1.2 isn’t deemed a variant of interest or concern yet by the WHO, but researchers are pushing the organization to watch it closely.

A team of scientists from South Africa detected the new variant, which was first observed in May and has since spread to seven other countries in Africa, Europe, Asia and Oceania, according to a preprint study that hasn’t yet been peer-reviewed.

“It’s still not clear where this came from,” noted Dr. Zain Chagla, an infectious diseases specialist with McMaster University in Hamilton. “It was first identified in South Africa but people need to know that South Africa has actually quite good sequencing networks and so it may not be the origin.”

A health-care worker fills a syringe with a dose of the AstraZeneca COVID-19 vaccine in Bogota, Colombia, on Aug. 15. The country first detected the mu variant back in January. (Luisa Gonzalez/Reuters)

Richard Lessells, an infectious disease specialist and one of the authors of the research on C.1.2, told Reuters the variant may have even more immune-evasion properties than delta, based on its pattern of mutations, and that the findings had been flagged to the WHO.

However, it’s not known yet if the variant is actually more contagious, or more capable of evading the immunity provided by either vaccines or a prior coronavirus infection.

“These things need time to see,” Chagla said. “Delta is incredibly fit, and incredibly virulent and replaces [other strains] aggressively. We still haven’t seen suggestions of this yet [with C.1.2].” 

WATCH | Herd immunity harder to achieve thanks to variants, says government scientist:

Herd immunity harder to achieve now because of new variants, says government scientist

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Speaking with Power & Politics, Chief Science Advisor of Canada Mona Nemer says that collective immunity is a moving target but will be difficult to achieve due to the emergence of new COVID variants. 2:02

How worried should Canadians be right now?

Given that delta makes up the lion’s share of Canada’s COVID-19 cases and there’s still much we don’t know about mu or C.1.2 — concerns over emerging variants need to be put into context.

Chagla said it’s important to keep studying and monitoring the C.1.2 variant, but “there’s no need for panic yet.”

There has been an increased spread of C.1.2, and it’s a rising percentage of sequenced cases in various countries outside of South Africa, Chagla said, but nothing on the scale of delta and it remains to be seen if we’ll experience more global spread. 

“It’s still not clear whether or not that just means there’s a lot of local spread amongst particular groups that just seems to be over-represented — or if it’s a legitimate growth pattern,” he added.

“We still don’t know, if you put things in the same pool, whether or not delta is going to be much more virulent.” 

Chagla says that much like other variants that have emerged over the course of the pandemic — including variants of concern like alpha, beta, lambda and, now, mu — they could either be overtaken by delta or “burn themselves out over time.” 

“Right now, it seems that there aren’t a large number of cases for [C.1.2],” Kelvin said. “But now that we have this identified, then surveillance centres around the world can start to determine, are they seeing numbers of these cases as well?” 

To figure out how often variant cases are appearing here, the Public Health Agency of Canada works with the provinces, territories, and the Canadian COVID-19 Genomics Network to sequence a percentage of all positive COVID-19 test results.

Sequencing reveals the genetic code of the virus, showing which variant was involved in a specific case of COVID-19, and those results are reported each week




Why do new variants matter in the global fight against COVID-19?

New variants have emerged 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 — and experts say this trend is likely to continue until more of the world is vaccinated.

“This is an incredibly big reminder — even if this is a false alarm — of what global vaccine equity means,” said Chagla. 

“Many of us starting to see the delta wave in Sub-Saharan Africa were very, very worried about what could come of that.”

WATCH | WHO calls for vaccine equity:

WHO comments on need for global COVID-19 vaccine equity

4 months ago

People in wealthier countries are getting vaccinated at a much faster rate than those in poorer countries despite efforts by the World Health Organization and the international community to make COVID-19 vaccine accessibility equitable around the world. 2:04

Chagla says the region has low vaccination levels, poor quality healthcare systems and a large population of immunocompromised individuals, with rates of HIV in some countries as high as 15 to 20 per cent of the adult population.

“That was kind of a mixing pot of bad scenarios to lead to the development of a variant … so I don’t think we can be surprised to see that something seems to have shown up,” he said. 

“And we kind of just watch it happen in that sense, and we continue to watch it happen.”

It’s also clear these variants don’t stay put.

Even if they emerge in one area of the world, cases later appear elsewhere — meaning other countries, including Canada, are eventually impacted yet again by this ever-evolving virus.


Have questions about this story? We’re answering as many as we can in the comments.


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'Waning immunity?' Some experts say term leads to false understanding of COVID-19 vaccines – CBC.ca

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The idea of waning immunity has picked up steam in recent weeks, with some countries using it to justify rolling out third-dose COVID-19 vaccine boosters to their populations. But immunologists say the concept has been largely misunderstood.

While antibodies — proteins created after infection or vaccination that help prevent future invasions from the pathogen — do level off over time, experts say that’s supposed to happen.

And it doesn’t mean we’re not protected against COVID-19.

Jennifer Gommerman, an immunologist with the University of Toronto, said the term “waning immunity” has given people a false understanding of how the immune system works.

“Waning has this connotation that something’s wrong, and there isn’t,” she said. “It’s very normal for the immune system to mount a response where a ton of antibodies are made and lots of immune cells expand. And for the moment, that kind of takes over.

WATCH | Waning immunity sparks debate about need for COVID-19 booster shots: 

Waning immunity sparks debate about need for COVID-19 booster shots

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Recent studies show a drop in effectiveness for COVID-19 vaccines, but the lack of information about how severe breakthrough cases were has sparked a debate about whether booster shots are necessary. 2:03

“But it has to contract, otherwise you wouldn’t have room for subsequent immune responses.”

Antibody levels ramp up in the “primary response” phase after vaccination or infection, “when your immune system is charged up and ready to attack,” said Steven Kerfoot, an associate professor of immunology at Western University in London, Ont.

Memory of pathogen remains

They then decrease from that “emergency phase,” he said. But the memory of the pathogen and the body’s ability to respond to it remain.

Kerfoot said B-cells, which make the antibodies, and T-cells, which limit the virus’s ability to cause serious damage, continue to work together to stave off severe disease long after a vaccine is administered. While T-cells can’t recognize the virus directly, they determine which cells are infected and kill them off quickly.

Recent studies have suggested the T-cell response is still robust several months following a COVID-19 vaccination.

“You might get a minor infection … [but] all of those cells are still there, which is why we’re still seeing very stable effectiveness when it comes to preventing severe disease,” Kerfoot said.

In the U.S., an advisory panel to the Food and Drug Administration overwhelmingly decided on Friday against offering Pfizer COVID-19 booster shots to most Americans — limiting third doses to those aged 65 and older or at high risk for severe disease. (Kirsty Wigglesworth/The Associated Press)

A pre-print study released this week by Public Health England suggested that protection against hospitalization and death remains much higher than protection against infection, even among older adults.

So the concept of waning immunity depends on whether you’re measuring protection against infection or against severe disease, Kerfoot said.

Ontario reported 43 hospitalized breakthrough cases among the fully vaccinated on Friday, compared with 256 unvaccinated hospitalized infections. There were 795 total new cases in the province that day, 582 among those who weren’t fully vaccinated or had an unknown vaccination status.

British Columbia, meanwhile, saw 53 fully vaccinated COVID-19 patients hospitalized over the last two weeks, compared with 318 unvaccinated patients.

“You’ll hear people say that vaccines aren’t designed to protect infection, they’re designed to prevent severe disease,” Kerfoot said. “I wouldn’t say necessarily it’s the vaccine that’s designed to do one or another … that’s just how the immune system works.”

Moderna, Pfizer back need for booster

Moderna released real-world data this week suggesting its vaccine was 96 per cent effective at preventing hospitalization, even amid the more transmissible delta variant, and 87 per cent effective at preventing infection — down from 94 per cent efficacy seen in clinical trials last year.

Moderna CEO Stéphane Bancel said that dip “illustrates the impact of waning immunity and supports the need for a booster to maintain high levels of protection.”

Pfizer-BioNTech has argued the same with its own data, and an advisory panel to the U.S.-based Food and Drug Administration voted Friday to endorse third doses for those aged 65 and older or at high risk for severe disease.

However, the panel rejected boosters for the general population, saying the pharmaceutical company had provided little safety data on extra jabs.

The University of Toronto’s Gommerman said the efficacy data presented by Moderna doesn’t signal the need for a third dose.

“The fact it protects 87 per cent against infection, that’s incredible,” she said. “Most vaccines can’t achieve that.”

Bancel said Moderna’s research, which has yet to be peer reviewed, suggested a booster dose could also extend the duration of the immune response by re-upping neutralizing antibody levels.

Looking beyond the antibody response

But Dr. Sumon Chakrabarti, an infectious physician in Mississauga, Ont., said looking solely at the antibody response is misleading and could be falsely used as justification for an infinite number of boosters.

Israel, which has opened third doses for its citizens, recently talked about administering fourth doses in the near future.

“This idea of waning immunity is being exploited, and it’s really concerning to see,” Chakrabarti said. “There’s this idea that antibodies mean immunity, and that’s true … but the background level of immunity, the durable T-cell stuff, hasn’t been stressed enough.”

While some experts maintain that boosters for the general population are premature, they agree some individuals would benefit from a third jab.

The National Advisory Committee on Immunization has recommended boosters for the immunocompromised, who don’t mount a robust immune response from a two-dose series.

Other experts have argued that residents of long-term care homes, who were prioritized when the rollout began last December, may also soon need a third dose. The English study suggests immunity could be waning in older groups but not much — if at all — among those under age 65.

Chakrabarti said a decrease in protection among older populations could be due more to “overlapping factors,” including their generally weaker immune systems and congregate-living situations for those in long-term care.

Immune cells live for years within bone marrow

“These are people at the highest risk of hospitalization,” he said. “Could [the length of time that’s passed following their doses] be playing a role? Yeah, maybe.”

While we still don’t know the duration of the immune response to COVID-19 vaccination, Gommerman said immune cells typically continue to live within bone marrow and make small amounts of antibodies for “decades.”

“And they can be quickly mobilized if they encounter a pathogen,” she said.

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Coronavirus cases in Quebec rise by 821 with three new deaths and two more hospitalizations – CTV News Montreal

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MONTREAL —
Quebec reported Saturday that 821 more people have tested positive for COVID-19 in the province, bringing the overall number of infections to 402,283.

Of the new infections, 609 people were unvaccinated when they received their positive result, 49 received one dose of vaccine more than two weeks prior, and 163 were double-vaxxed more than a week before the test. 

Hospitalizations rose by two bringing the total number of people receiving care in the province’s hospitals to 264. The ministry reports that 36 people checked in for care, and 34 were discharged. Of the 36, 28 were unvaccinated, two received one vaccine dose more than 14 days prior and six got both jabs more than a week before entering the hospital. 

There are 89 people in intensive care wards, which is six fewer than on Friday.

Three more people have died due to COVID-19, bringing that total to 11,321 since March 2020.

There are 508 active outbreaks in the province.

Quebec’s vaccination rate remains at 88 per cent for one dose of the eligible population and 82 per cent for both doses. 

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Spike in COVID-19 cases is pushing New Brunswick's health-care system to the limit – CTV News Atlantic

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MONCTON, N.B. —
New Brunswick’s jump in COVID-19 cases has overloaded the health-care system this week.

The Horizon Health Network is now looking to hire more staff across the province to help with the growing demand for testing and vaccinations.

The health network has seen an increased demand in testing as COVID-19 cases have soared over the last month.

“Two weeks ago, if you wanted a test, you could walk in or call and get it at almost anytime you wanted,” said Dr. Jeff Steeves with New Brunswick’s Medical Society.

But now, assessment centres are seeing long line ups and delays in testing.

Steeves wants people to get the jab and practice caution during this time to prevent overloading the system even more.

“Remember, we were running short even before COVID, so we’re trying to maintain that,” Steeves said. “Therefore, we can’t divert the staff like we did before, hence the call for new staff.”

Horizon Health’s vice-president said in a statement Friday that they are currently looking to recruit staff at vaccination clinics, assessment centres and school clinics in Moncton, Saint John and Fredericton.

“Given the recent rise in COVID activity in New Brunswick, and the increased demand for these services, we are hoping to replenish our pool of available clinicians and administrative support staff as we ramp up activity at these locations,” said Jean Daigle.

Since the province announced proof of vaccination requirements this week, public health has reported a significant jump in vaccination appointments.

On Wednesday, 1,700 appointments were booked, while yesterday there were 1,929.

Health officials say prior to Wednesday’s number, the recent average for vaccinations was 600 bookings per day. On Thursday, 600 additional vaccines had to be delivered to a clinic in Moncton.

“Things have picked up dramatically,” said Fredericton pharmacist Alistair Bursary, who says they’ve been busy taking calls from people looking to get their first or second dose.

“So, whereas we were doing perhaps 10 patients a day on average now we are probably going to hit 40-50 just at our pharmacy alone,” Bursary said.

While the demand for services continue to climb, those working on the frontlines hope to get the help they need sooner rather than later.

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