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Study suggests vaccines may improve symptoms for some COVID-19 long-haulers

Elaine McCartney typically keeps a list on hand of her 30 or so health issues following a bout of COVID-19 a year ago— in part because she just can’t keep track of them all.

There’s the severe fatigue and memory issues. Brain fog, much like after a concussion. Constant headaches, low appetite, round-the-clock dizziness. And on and on.

The 65-year-old from Guelph, Ont., has been experiencing those symptoms for close to a year, after developing what felt like a severe case of influenza in April 2020 and which a physician identified as a probable case of the COVID-19 illness. 

Then last month she got her first dose of the Pfizer-BioNTech vaccine. Her condition quickly seemed to improve.

“I was able to go to the store on my own, which I haven’t done for eight months,” McCartney said. “And my energy was up, and my pain was less. I had chronic debilitating pain in my shoulder, and it was gone.”

McCartney’s experience may offer a glimmer of hope for a growing number of people around the world living with prolonged health concerns after being infected with the virus causing the COVID-19 illness.

She’s not the only patient seeing unexpected improvements. Emerging research suggests vaccines may reduce symptoms for some of those suffering from what is now being called “long COVID”, where patients continue to suffer from a range of health concerns long after the infectious phase of the illness has passed. 

‘Reassuring’ findings from U.K. study

More than a year into the pandemic, it’s not clear how many people are experiencing long-term health issues after having COVID-19, but their numbers are growing.

Researchers think around 10 per cent of people who get sick with COVID-19 continue to live with lasting symptoms — some suggest the number could be as high as 30 per cent — which could mean millions worldwide are coping with some lingering issues from the disease.

A new preprint study out of the U.K., which is still awaiting the peer review process, looked at a small group of such “long COVID” patients. It found those who had received at least one dose of the vaccine had “a small overall improvement” in long COVID symptoms and a “decrease in worsening symptoms” when compared to the unvaccinated patients.

The researchers followed 66 hospitalized patients whose symptoms persisted — issues like fatigue, breathlessness, and insomnia — including 44 who got vaccinated and 22 who didn’t.


Emerging research suggests vaccines may reduce symptoms for some of those suffering from “long Covid”, or lingering symptoms after a bout of COVID-19. (Evan Mitsui/CBC)

A little over 23 per cent of the vaccinated patients saw some resolution of their symptoms, the researchers noted, compared to around 15 per cent of those who weren’t vaccinated — with no difference in response identified between the Pfizer-BioNTech or Oxford-AstraZeneca vaccines used among the participants.

The team also found another “reassuring result” — fewer vaccinated patients reported any worsening symptoms during the time period studied than the unvaccinated group, though they cautioned that there was a large potential for bias given patients self-reported their symptoms. 

Dr. Fergus Hamilton, an infectious diseases researcher at the University of Bristol Medical School and part of the team behind the new study, said the findings offer a “slight hint” that vaccines might improve lingering symptoms.

“Although we’re a bit suspicious about that given the small numbers,” he added.

Science behind vaccine impact not clear

The study is limited by its small sample size, but other medical experts are observing a similar trend.

In the U.S., where roughly a quarter of the population is fully vaccinated, physicians now have a large pool of patients to follow.

Dr. Daniel Griffin, an infectious diseases physician at Columbia University in New York, said around 40 per cent of the patients he is treating for lingering health issues from COVID-19 are reporting either complete, or significant, improvement in their symptoms after being fully vaccinated.

He said the numbers in the U.K. study were “pretty on-target” with what he initially observed in his own patients, but that the impact seemed to bump up a couple weeks after people got their second dose.

“That’s the first bit of good news in a really a long time,” Griffin said.

But he acknowledged the mechanics behind why vaccination might clear up lingering COVID-19 symptoms isn’t yet clear.

WATCH | Long-COVID sufferers struggle with limited care options:

Kim Clark and Sonja Mally have jumped from specialist to specialist for the past year as they’ve sought relief for a series of crippling symptoms associated with post-acute COVID-19 syndrome. Some health experts say more dedicated funding and resources for COVID long-haulers would help sufferers like them and shed light on a little-understood aspect of the pandemic. 2:27

“I think the most persuasive theory for me is that the virus was never completely cleared, or whatever remnants might still be … are now able to be cleared because of the robust response that’s triggered by the vaccines,” Griffin said.

McCartney said her own post-vaccination experience felt nothing short of a miracle — even if the science behind what’s happening in her body remains hazy and more research needed to evaluate how much vaccines could actually help COVID long-haulers going forward.

“I was feeling so miserable, for so long,” she said.

“I’ve logged more than a thousand steps in the past four days and I haven’t done that for months and months and months — so I’ve definitely seen improvement.”

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NASA Begins Assembling Spacecraft to Study Enormous Metallic Asteroid

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NASA’s Jet Propulsion Laboratory (JPL) in California got a package last week, and it’s much more important than the smattering of Amazon impulse purchases that show up on most of our doorsteps. JPL has taken delivery of the Psyche spacecraft from Maxar Technologies and is now starting final assembly. Next year, this piece of hardware will ride a SpaceX rocket into orbit, and then it’s off to the asteroid belt to study its namesake, the metal-rich asteroid 16 Psyche. 

JPL is shooting for an August 2022 launch for Psyche, which will start it on a nearly four-year journey to the asteroid belt between Mars and Jupiter. Along the way, it will pass within just 500 kilometers of Mars. Then, it’s on to 16 Psyche, the heaviest known M-type asteroid that all by itself has about 1 percent of the asteroid belt’s mass thanks to its mostly iron-nickel composition. Scientists believe that Psyche is the exposed core of a protoplanet that collided with another object in the distant past, stripping away its outer crust.

The chance to study a planetary core up close, even one that’s been exposed to space for billions of years, is something NASA couldn’t pass up. The agency chose Psyche as part of the Discovery program in 2017. Missions under the Discovery banner are cheaper than those in New Frontiers or Flagship programs, which can run into the billions of dollars. Psyche is expected to cost around $ 117 million, including launch aboard a SpaceX Falcon Heavy rocket. 

Psyche is an average of 111 km (69 miles) in diameter with a maximum diameter of 277 km, making it larger than the states of Rhode Island and Delaware.

The newly arrived construct at JPL is what’s known as the Solar Electric Propulsion (SEP) Chassis. This large, boxy module accounts for more than 80 percent of the total spacecraft mass and includes fully integrated propulsion, navigation, thermal, and electrical systems. Now it’s up to JPL engineers to complete the spacecraft by integrating communication, scientific instruments, and other systems. Psyche will reach its destination with the help of an SPT-140 engine, a Hall-effect thruster that uses solar power to accelerate xenon ions to produce thrust. It’s not much thrust — the SPT-140’s thrust is measured in micro-newtons — but it can accelerate continuously for long periods. 

Psyche will use three instruments to study the asteroid: a multispectral imager to take photos of the surface, a gamma-ray spectrometer to analyze the asteroid’s elemental composition, and a magnetometer to measure its magnetic field. The image above is just an artist’s rendering, so we don’t know what the spacecraft will discover when reaching its eponymous asteroid. Regardless, this mission could change our understanding of planetary formation.

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Pfizer study suggests COVID-19 vaccine is safe, protective in younger teens

Pfizer announced Wednesday that its COVID-19 vaccine is safe and strongly protective in kids as young as 12, a step toward possibly beginning shots in this age group before they head back to school in the fall.

Most COVID-19 vaccines being rolled out worldwide are for adults, who are at higher risk from the novel coronavirus. Pfizer’s vaccine is authorized for ages 16 and older. 

In a study of 2,260 U.S. volunteers ages 12 to 15, preliminary data showed there were no cases of COVID-19 among fully vaccinated adolescents compared to 18 among those given dummy shots, Pfizer reported in a press release on Wednesday.

It’s a small study, that hasn’t yet been published, so another important piece of evidence is how well the shots revved up the kids’ immune systems. Researchers reported “robust antibody responses,” the release said. 

Kids had side effects similar to young adults, the company said. The main side effects are pain, fever, chills and fatigue, particularly after the second dose. The study will continue to track participants for two years for more information about long-term protection and safety.

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Pediatric studies underway for other vaccines 

Pfizer and its German partner BioNTech in the coming weeks plan to ask the U.S. Food and Drug Administration and European regulators to allow emergency use of the shots starting at age 12.

“We share the urgency to expand the use of our vaccine,” Pfizer CEO Albert Bourla said in a statement. He expressed “the hope of starting to vaccinate this age group before the start of the next school year” in the United States.

Pfizer isn’t the only company seeking to lower the age limit for its vaccine. Results also are expected soon from a U.S. study of Moderna’s vaccine in 12- to 17-year-olds.

But in a sign that the findings were promising, the FDA already allowed both companies to begin U.S. studies in children 11 and younger, working their way to as young as six months old.

AstraZeneca last month began a study of its vaccine among 6- to 17-year-olds in Britain. Johnson & Johnson is planning its own pediatric studies. And in China, Sinovac recently announced it has submitted preliminary data to Chinese regulators showing its vaccine is safe in children as young as three.

While most COVID-19 vaccines being used globally were first tested in tens of thousands of adults, pediatric studies won’t need to be nearly as large. Scientists have safety information from those studies and from subsequent vaccinations in millions more adults.

One key question is the dosage: Pfizer gave the 12-and-older participants the same dose adults receive, while testing different doses in younger children.

U.S. FDA timeline not clear

It’s not clear how quickly the FDA would act on Pfizer’s request to allow vaccination starting at age 12. Another question is when the country would have enough supply of shots — and people to get them into adolescents’ arms — to let kids start getting in line.

Supplies are set to steadily increase over the spring and summer, at the same time states are opening vaccinations to younger, healthier adults who until now haven’t had a turn.

Children represent about 13 per cent of COVID-19 cases documented in the U.S. And while children are far less likely than adults to get seriously ill, at least 268 have died from COVID-19 in the U.S. alone and more than 13,500 have been hospitalized, according to a tally by the American Academy of Pediatrics. That’s more than die from the flu in an average year. Additionally, a small number have developed a serious inflammatory condition linked to the coronavirus.


Caleb Chung, seen in this December 2020 photo as he gets his first dose of either the Pfizer vaccine or a placebo, says the study was, ‘was really somewhere that I could actually help out.’ (Richard Chung/The Associated Press)

Caleb Chung, who turns 13 later this week, agreed to volunteer after his father, a Duke University pediatrician, presented the option. He doesn’t know if he received the vaccine or a placebo.

“Usually I’m just at home doing online school and there’s not much I can really do to fight back against the virus,” Caleb said in a recent interview. The study “was really somewhere that I could actually help out.”

His father, Dr. Richard Chung, said he’s proud of his son and all the other children volunteering for the needle pricks, blood tests and other tasks a study entails.

“We need kids to do these trials so that kids can get protected. Adults can’t do that for them,” Chung said.


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


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New Study Proposes Warp Drive That Might Actually Work

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(Credit: Eduard Muzhevskyi/Getty Images) 
Exploring the universe in Star Trek is as easy as firing up the warp drive and zipping off to the next adventure, but real life is much more tedious without faster-than-light (FTL) travel. Physicists have speculated on the possibility of a real warp drive for years, but a new paper lays out a vision for a warp drive that might actually work. We still don’t know how to build it, but at least we know why we can’t build it yet.

Let’s say you want to visit Proxima Centauri, which is the closest alien solar system. It’s four light-years away, which works out to trillions of kilometers, or miles, or leagues, or whatever — in the trillions, it doesn’t really matter. It’s very, very far away. It would take millennia to reach Proxima Centauri with current technology, but if you can move faster than light, you could be there in no time. The problem is physics: General relativity says that nothing can go faster than light, a claim that has thus far held up to scientific scrutiny. 

In 1994 theoretical physicist Miguel Alcubierre proposed a model for a warp drive vessel that didn’t violate the laws of the universe, but it required exotic negative energy that we can’t produce (it may not even be possible). A new paper from physicists Alexey Bobrick and Gianni Martire started making the rounds late last year, claiming that a physical warp drive may indeed be possible. That paper has now been peer-reviewed and published in the journal Classical and Quantum Gravity.

Unlike the Alcubierre Drive, the Bobrick-Martire version doesn’t require unfathomable amounts of negative energy. The paper doesn’t describe a vessel but rather a bubble of spacetime that could surround a vessel, a person, or anything else. The bubble (above) can behave however it likes, including accelerating to speeds faster than light. At least, that’s how it would look to an outside observer. To anyone inside the bubble, the laws of physics would remain intact as the “passenger area” consists of completely flat spacetime. Physicist Sabine Hossenfelder (below) broke the paper down when it first began circulating a few months ago. 

There are still problems to work out here, so don’t start packing for your space adventure quite yet. We don’t know how to make a spacetime bubble. The matter and energy distribution in such a structure are still a mystery. Even if we could make such an object, we’d have to find the right geometry to accelerate it efficiently. Something as small as the way people are sitting inside a warp bubble could change the amount of energy required. 

The important thing is that the Bobrick-Martire Drive gives us a stronger mathematical basis for studying the possibility of FTL travel. Physicists who are adept at sniffing out silly space travel hypotheses have given this paper their stamp of approval, and it will no doubt spur others to add their two cents. In Star Trek, they didn’t develop warp drive until 2063. We’ve got some time yet.

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Planet Nine Hypothesis Takes a Major Hit in New Study

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It used to be easy to know how many planets there were: nine. It had been nine planets for an entire generation before scientists started rethinking what counts as a planet. Pluto is out, but some astronomers believe there’s a real ninth planet lurking out there. Others aren’t convinced, and the debate is starting to shift in favor of the planet nine skeptics

To be clear, there have been crackpots who, at various times, have claimed that a tenth (or ninth) planet was going to collide with Earth. The scientific debate over Planet Nine focuses on a 2016 study penned by astronomers Michael Brown and Konstantin Batygin. In it, the pair shows how the unusual orbits of numerous extreme trans-Neptunian objects (ETNO) could be the result of a massive, undiscovered object in the outer solar system. 

Other scientists were understandably skeptical of these claims, but the evidence presented by Brown and Batygin wasn’t as easy to dismiss as conspiracy theories about Planet X. The orbits cited in the study are odd, and they do support the idea there’s a massive something out there. We don’t know it’s a planet, though, and the math suggests it should be substantially larger than Earth. So where is it?! Some scientists have speculated that Planet Nine may actually be a small black hole — after all, the only evidence we have for Planet Nine is gravity. 

A new pre-print study led by the University of Michigan’s Kevin Napier posits an alternative explanation. Perhaps, the team says, the supposed clustering of ETNO orbits in the outer solar system is an illusion caused by biased data. According to Napier, it’s very hard to spot the tiny ETNOs at such great distances. So, astronomers have to adjust their telescopes to focus on specific parts of the sky, taking note of both the time of day and year. The result is allegedly an incomplete view of ETNOs. So, the clustering isn’t really clustering — those are just the objects Brown and Batygin happened to catalog. 

Planet Nine may be the cause of the clustering of ETNO orbits.

The team went a step further by checking in on 14 ETNOs that were not included in the initial Planet Nine paper. They found no indication these objects were being affected by the supposed Planet Nine. 

This study still needs to be peer-reviewed, but the team seems confident. Some of them are even out there talking smack on Twitter. Time will tell who’s right about this, but the Planet Nine supporters are going to need some new evidence to keep up the fight.

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Moderna study suggests half doses offer strong immune response, but experts caution against changing approach

There’s now early evidence showing Moderna’s coronavirus vaccine may elicit a strong immune response even through half doses, prompting hope that further research could back up the results and eventually allow countries like Canada to stretch out vaccine supplies.

The company’s peer-reviewed findings, based on a Phase 2 trial, were published online by the journal Vaccine last week.

The study looked at the mRNA vaccine’s “immunogenicity” — its ability to provoke an immune response — through both anti-virus, spike-binding antibody levels and neutralizing antibodies, which help to block reinfection.

Researchers determined within a two-dose regimen that both the current amount of vaccine dose and half that amount being given each time were capable of “significant” immune responses.

Those findings are welcome news, though not yet worth changing dosing approaches, said Dr. Zain Chagla, an infectious disease specialist and associate professor at McMaster University in Hamilton.

“But it does bring up the urgent need to do a Phase 3-type clinical trial of full dose versus half dose and see what happens,” he said. 

“The implications, obviously, are you all of a sudden double your vaccine supply overnight if this seems to work out.”


During a recent study, researchers determined that half the amount of Moderna’s COVID-19 vaccine dose was capable of triggering a ‘significant’ immune response. (Jean-Francois Badias/The Associated Press)

Immune response ‘increased substantially’

The Moderna vaccine is one of two options currently approved and being used in Canada to combat the spread of COVID-19, with more than 40 million doses ordered by the federal government.

Based on full clinical trial results, the current approach requires two doses of the vaccine, spaced 28 days apart.

The company’s recently released findings looked at both a full dose of 100 micrograms and a half dose of 50 micrograms, given as two doses in a randomized, observer-blind, placebo-controlled trial.

At eight different U.S. sites, a total of 600 participants were divided into age cohorts and randomly assigned at a 1:1:1 ratio to receive either the two full doses, two half doses, or two placebo doses.

By 28 days after the first shot, anti-virus spike-binding antibody levels and neutralizing antibodies were higher among people who’d been given the full dose compared to the half dose.

But that difference was “less apparent” after participants received both rounds, Moderna’s research team found.  

Both binding antibodies and neutralizing antibodies “increased substantially” by the two-week mark after participants were fully vaccinated and remained elevated through day 57, the researchers wrote.


Boxes containing the Moderna COVID-19 vaccine are prepared to be shipped at a distribution centre in Olive Branch, Miss., in late December. (Paul Sancya/Reuters)

Questions over duration of protection, variants

Outside experts who spoke to CBC News all stressed the need for future research before changing Canada’s dosing approach, given the short two-month time period and small, homogeneous group studied by Moderna. 

Chagla also said there’s a clear need to understand longer-term immunity and how other elements of the immune system — such as T-cells, which target specific bodily invaders — might be affected as well.

“The point nobody can answer for you is how long you will have protection,” said Horacio Bach, an adjunct professor in the division of infectious diseases at the University of British Columbia’s faculty of medicine.

“Nobody knows. Nobody can tell you. There are no studies; that’s the reason it’s a global emergency.”

Dr. Noni MacDonald, a researcher focused on vaccine safety who is also a professor at Dalhousie University’s department of pediatrics in Halifax, stressed that while Moderna’s study did show similar immunogenicity with two different concentrations of the vaccine, it was also based on “old data.”

The research was conducted between late May and early July 2020 — long before the clear rise of multiple virus variants, which may be more transmissible or capable of evading the body’s immune response.

If the findings hold up against emerging variants, it could mean countries like Canada could one day “stretch what we have” when it comes to Moderna shipments, MacDonald said in an email exchange with CBC News.

But right now, that’s not yet a possibility. Already the company says its vaccine may be less effective against the B1351 variant, requiring it to develop an alternative version for booster shots.

Immunologist and microbiologist Nikhil Thomas says it’s important to ‘suppress the spread of these variants,’ as the coronavirus variant first identified in the U.K. is replicating faster and transmitting ‘at a higher frequency.’ 4:17

U.S. officials discussed half-dosing

Despite limited data on the benefits of using half-doses, particularly against emerging variants, there has been discussion south of the border over taking that approach, with the U.S. government also helping fund Moderna’s most recently-published research.

In January, Moncef Slaoui, then-chief adviser of the former U.S. president Donald Trump administration’s vaccine effort — one dubbed Operation Warp Speed — said officials were considering giving half-doses of the Moderna vaccine to American adults under the age of 55.

The same month, the U.S. Food & Drug Administration released a statement shooting that idea down, saying any changes to dosing or schedules of approved vaccines would be “premature and not rooted solidly in the available evidence.”

On this side of the border, Health Canada officials told CBC News the agency has not received an application from Moderna to amend its vaccine authorization, but would “thoroughly review” one if it was submitted.

Canada has other vaccines in line for approval — how they compare to the ones already being rolled out and how COVID-19 variants are a complicating factor. 2:03

Dosing strategies have long-term impact

While Bach suspects full clinical trials might yield a similar result to Moderna’s Phase 2 trial, he said it isn’t clear if the manufacturer would even allow countries to stretch their supplies.

He also agreed keeping the current guidelines in place is the ideal approach for the time being, rather than risking lives by adopting a dosing strategy that needs more evidence.

“We don’t know where we are going,” Bach said. “You can put people in danger.”

Still, there’s some potential in Moderna’s early results, according to Chagla. 

Knowing the adequate dosing strategy will matter down the line while developing those boosters for variants, he said. And the early evidence points to the potential for increasing vaccine supply to much of the developing world, where shots remain in short supply.

“The answer will have implicating effects for years, not just the vaccine roll-out over the next few months,” Chagla said.

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Roche arthritis drug cuts deaths in hospitalized COVID-19 patients, study suggests

Roche’s arthritis drug tocilizumab cuts the risk of death among patients hospitalized with severe COVID-19, also shortening the time to recovery and reducing the need for mechanical ventilation, results of a large trial showed on Thursday.

The findings — from the U.K.-based RECOVERY trial, which has been testing a range of potential treatments for COVID-19 since March 2020 — should help clear up confusion about whether tocilizumab has any benefit for COVID-19 patients after a slew of recent mixed trial results.

“We now know that the benefits of tocilizumab extend to all COVID patients with low oxygen levels and significant inflammation,” said Peter Horby, a professor of emerging infectious diseases at Oxford University and the joint lead investigator on the RECOVERY trial.

In June last year, the RECOVERY trial found that the cheap and widely available steroid dexamethasone reduced death rates by around a third among the most severely ill COVID-19 patients. That drug has since rapidly became part of standard-of-care recommended for severe patients.

Tocilizumab, sold under the brand name Actemra, is an intravenous anti-inflammatory monoclonal antibody drug used to treat rheumatoid arthritis. It was added to the trial in April 2020 for patients with COVID-19 who required oxygen and had evidence of inflammation.

The study included from 2,022 COVID-19 patients who were randomly allocated to receive tocilizumab by intravenous infusion, and who were compared with 2,094 patients randomly allocated to usual care alone. Researchers said 82 per cent of all patients were taking a systemic steroid such as dexamethasone.

Results showed that treatment with tocilizumab significantly reduced deaths — with 596 (29 per cent) of the patients in the tocilizumab group dying within 28 days, compared with 694 (33 per cent) patients in the usual care group.

This translates to an absolute difference of four per cent. It also means that for every 25 patients treated with tocilizumab, one additional life would be saved, Horby and his co-lead investigator Martin Landray said.

They added that benefits of tocilizumab were clearly seen to be in addition to those of steroids.

WATCH | Progress and setbacks in treating COVID-19:

While vaccines can prevent recipients from getting sick, finding and approving treatments for the virus has been difficult. 2:06

“Used in combination, the impact is substantial,” said Landray, who is also an Oxford professor of medicine and epidemiology.

Roche’s drug division chief Bill Anderson said last week that previous mixed results were likely due to differences in the type of patients studied, when they were treated, and the endpoint — the juncture at which success or failure is measured.

“We think we’re sort of zooming in on both the most relevant endpoints and relevant patient population,” Anderson said. “It seems like the ideal candidates are patients who are really in that acute phase of inflammatory attack.”

Drug used for some patients with COVID-19 in Canada

Actemra, along with Sanofi’s similar drug Kevzara, was authorized by Britain’s NHS in early January for COVID-19 patients in intensive care units after preliminary data from a smaller study called REMAP-CAP indicated it could reduce hospital stays by about 10 days.

The researchers said preliminary results will be made available on the medRxiv preprint server shortly and submitted to a peer-reviewed medical journal.

Dr. Niall Ferguson, head of critical care at Toronto’s University Health Network and Sinai Health System, sees potential in early data for tocilizumab, which is approved for use in Canada to treat rheumatoid arthritis.

Although evolving data has been mixed and is still emerging, Ferguson noted last week that the monoclonal antibody is already being used off-label for some severe patients in Toronto.

“It’s happening on a bit of an ad hoc basis when patients are caught at the right time and look like they may have a bit of
additional inflammation going on that could be set aside with this drug,” said Ferguson, who looks after the most severe COVID-19 cases at Toronto General Hospital.

Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine who was not directly involved in the U.K. trial, said its results were important.
 
“It is a large trial and the benefits were seen both on earlier discharge from hospital and mortality,” he said. “The 
magnitude of benefit is not startling but is clinically important, with a reduction in deaths from 33 per cent to 29 per cent.” 
 

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Study offers ‘promising’ evidence that at least 1 COVID-19 vaccine may curb virus transmission

Real-world findings are starting to back expectations for the level of protection provided by several leading coronavirus vaccines, but there’s still a burning question among scientists: Could the shots actually reduce virus transmission as well?

New research out of Israel offers early clues that at least one vaccine — the mRNA-based option from Pfizer-BioNTech, which is also being used here in Canada — may lead to lower viral loads, suggesting it might be harder for someone to spread the virus if they get infected post-vaccination.

In a study released publicly on Monday as an unpublished, non-peer-reviewed preprint, a team of researchers from the Israel Institute of Technology, Tel Aviv University and Maccabi Healthcare Services found the viral load was reduced four-fold for infections that occur 12 to 28 days after a first dose of the vaccine.

“These reduced viral loads hint to lower infectiousness, further contributing to vaccine impact on virus spread,” the researchers wrote.

Virologist Jason Kindrachuk, an assistant professor in the department of medical microbiology at the University of Manitoba, said it’s been a waiting game to figure out whether the protection from illness offered by mRNA vaccines might also curb transmission — a key tool for winding down the pandemic.

“So the data from this, I think, is important,” he said. “It doesn’t answer all the questions, but it starts to tell us that there actually might be some added benefit to these vaccines beyond just reducing severe disease.”

Toronto-based infectious disease specialist Dr. Isaac Bogoch, a member of Ontario’s vaccine task force, agreed these early findings — which still require peer-review — aren’t a scientific “home run,” but do offer hope in the fight against COVID-19.

“This would point in the direction that people who have been vaccinated, who are still infected, may be less likely to transmit starting at about 12 days after their vaccine,” he said.

‘Significantly reduced’ viral loads

Israel is among the world leaders for COVID-19 vaccination rates, with Maccabi Healthcare Services vaccinating more than 650,000 people by Jan. 25, the paper noted, giving the researchers a large pool of data compared to what exists so far in many other countries. 

The team analyzed COVID-19 test results from roughly 2,900 people between the ages of 16 and 89, comparing the cycle threshold values of post-vaccination infections after a first dose with those of positive tests from unvaccinated patients.

So, what are cycle threshold values, and how does that potentially tie to viral loads and virus transmission?

Standard polymerase chain reaction (PCR) tests for COVID-19 identify the viral infection by amplifying the virus’s RNA until it hits a level where it can be detected by the test. Multiple rounds of amplification may be required — and the cycle threshold value refers to the number of rounds needed to spot the virus.


Toronto-based infectious disease specialist Dr. Isaac Bogoch, a member of Ontario’s vaccine task force, agrees these early findings — which still require peer-review — offer some hope in the fight against COVID-19. (Maggie MacPherson/CBC)

“If you can detect the virus with very few cycles, there’s probably a lot of virus there,” Bogoch explained. “If you need to keep looking and looking and looking and looking for it, it might be there — it’s just a lot harder to find evidence of the virus genetic material.”

A higher cycle threshold, then, usually means there’s less virus genetic material present, which usually translates to people being less contagious, he said.

Based on an analysis comparing post-vaccination test results up to Day 11 to the unvaccinated control group, the Israeli researchers found “no significant difference” in the distribution of cycle threshold values for several viral genes.

That changed by 12 days after vaccination, with the team finding a “significant” increase in cycle thresholds up to 28 days later.


A team of researchers from the Israel Institute of Technology, Tel Aviv University and Maccabi Healthcare Services found the viral load was reduced four-fold for infections happening 12 to 28 days after a first dose of the Pfizer-BioNTech mRNA vaccine. The findings have yet to be peer-reviewed and published in a medical journal. (Evan Mitsui/CBC News)

The result suggests infections occurring 12 days or longer following just one vaccine dose have “significantly reduced viral loads, potentially affecting viral shedding and contagiousness as well as severity of the disease,” the team concluded.

It’s a finding that appears to mimic the efficacy of the Pfizer-BioNTech vaccine in its clinical trials, which offered some early protection starting 12 days after the first dose and fully kicks in a week after the second shot, with a reported efficacy of around 95 per cent.

More research needed, experts say

The observational study was not a randomized controlled trial — meaning researchers couldn’t conclude a direct cause-and-effect relationship — and has not yet been published in a scientific journal. The research also has notable limitations, its authors acknowledged. 

For one, the group of vaccinated individuals may differ in key ways from the demographically matched control group, such as their general health. The study also didn’t account for variants of the virus that may be associated with different viral loads, the team wrote.

Indeed, those variants are already proving to be roadblocks in the fight against COVID-19, with concerns ranging from higher transmissibility to reduced vaccine efficacy, including concern in South Africa and beyond after a small and yet-to-be-published study suggested the Oxford-AstraZeneca vaccine offered minimal protection against mild infection from the country’s now-dominant B1351 variant. 

With those concerns in mind, experts who spoke with CBC News about the Israeli study stressed that more research is needed to back up the results on a broader scale, and among diverse populations, before being used to fuel policy changes or current approaches to vaccination efforts.

“The data needs to be reviewed by experts and confirmed that it stands up to the quality that we would want to make a conclusion,” said vaccinologist Alyson Kelvin, an assistant professor at Dalhousie University in Halifax who works with Canadian vaccine developer VIDO-InterVac in Saskatoon.

WATCH | The impact of variants on the race to vaccinate: 

South Africa has halted its rollout of the AstraZeneca COVID-19 vaccine after a study showed it offered minimal protection against mild infection from a variant spreading there. While experts say it’s cause for concern, they say vaccines can be reconfigured to protect against mutations. 2:01

Even so, Kelvin said the data appeared to be treated with the necessary caution, and offers “promising evidence,” while Kindrachuk remains optimistic as well that the findings could prove a useful starting point.

“While we still have to have people using masks, and while we still have to have people distanced, the vaccines may actually also be able to reduce transmission,” he said. 

“So, those trends that we’re hoping to see, in regards to trying to curb community transmission for SARS-CoV-2, may be accelerated with a vaccine — and that will hopefully help us get out of this a little bit sooner.”


The Current21:46Vaccine concerns in South Africa

South Africa is facing another hurdle in its fight against COVID-19 after a new study suggested the Oxford-AstraZeneca vaccine is largely ineffective against the dominant variant spreading in that country. Dr. Rinesh Chetty, who works on the front lines of the pandemic in Durban, South Africa, weighs in on the findings. And Dr. Gerald Evans, an infectious disease specialist at Queen’s University and the Kingston Health Sciences Centre, tells us what it means for Canada’s vaccination efforts. 21:46

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Scientists Can Finally Study Einsteinium 69 Years After Its Discovery

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The 20th century was notable for numerous reasons, not least of which that humanity split the atom. In the remnants of atomic explosions, scientists found never-before-seen elements like einsteinium. Now, almost 70 years after its discovery, scientists have collected enough einsteinium to conduct some basic analysis

Scientists understood that something should exist on the periodic table where einsteinium sits (atomic number 99), but the material had never been identified before 1952, which is when the United States set off the “Ivy Mike” thermonuclear bomb in the Marshall Islands (see above). However, einsteinium is extremely unstable, and it decayed before we could learn much about it. That’s been the case for the intervening 69 years, until now. 

We no longer have to make einsteinium with hydrogen bombs, thank goodness. Scientists have a regular, if meager, source of einsteinium from Oak Ridge National Laboratory’s High Flux Isotope Reactor. This device is used to produce heavy elements like californium (atomic number 98). Scientists make californium because it’s an excellent source of neutrons, but the process also yields some einsteinium. Usually, einsteinium is mixed up with other materials and decays rapidly into berkelium and then into californium. 

Researchers from Lawrence Berkeley National Laboratory managed to isolate a tiny sample of pure einsteinium, a mere 200 nanograms. Previously, 1,000 nanograms was considered the smallest sample suitable for analysis, but the team prepared their einsteinium for testing and completed an X-ray absorption spectroscopy series. The sample showed a blueshift in the emitted light, meaning the wavelength was shortened. They expected a redshift; longer wavelengths. This suggests einsteinium’s bond distances are a bit shorter than predicted based on nearby elements on the periodic table. 

A tiny sample of einsteinium. It glows from the intense radiation as it decays.

So that’s potentially fascinating science! But the coronavirus pandemic ruined the experiment as it has so many other things in the past year. The team was unable to complete X-ray diffraction testing that would have told us more about the electron and molecular bond structures of einsteinium before the lab was closed. When the team was again able to access their experiment, too much of the sample had decayed into californium — einsteinium decays at a rate of about 3.3 percent each day. Therefore, the contaminated sample was no longer suitable for testing. 

The good news is more einsteinium will be available from the reactor every few months. This first step will pave the way for future research on this mysterious element.

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New Study Suggests Dark Matter Doesn’t Exist

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Time and time again, the predictions made by scientific luminaries like Einstein and Newton have been confirmed through experimentation. One place where the greats seem to fall a bit short is gravity — what we see doesn’t quite match the models. Most scientists currently believe the iron grip of gravity is augmented by dark matter, an invisible material that makes up about 85 percent of the universe. A new study makes the case for an alternative model, one in which dark matter doesn’t exist, and gravity works a little differently than we thought. 

Interest in dark matter can be traced back to the 1930s when Swiss astrophysicist Fritz Zwicky was unable to explain the faster-than-expected rotation of galaxy clusters. Based on what we understand of the underpinnings of gravity, the force should be proportional to mass. Since dark matter only interacts with normal matter via gravity, it plugs the hole in the model quite ably. But what if there is no dark matter out there?

The leading alternative to dark matter is known as Modified Newtonian Dynamics (MOND), and it’s getting a boost from the new study. At its most basic level, MOND claims we are missing an important aspect of gravity. Instead of gravity depending only on the mass of an object, it might also depend on the gravitational pull of other massive objects in the universe. This interaction, known as the External Field Effect (EFE), means that gravity at low accelerations is stronger than Newton or Einstein predicted. 

NGC 2841

The study went looking for evidence for modified gravity in 153 galaxies by calculating the field effects under MOND. Some galaxies should have greater apparent gravity as a result of EFE based on the mass of other nearby objects. The team reports that the galaxies predicted to have strong external fields slowed more frequently than those with weaker external fields, which is what you’d expect if MOND is right. The researchers claim no other theory has anticipated this behavior. 

This result doesn’t spell the end for dark matter — most scientists are expressing understandable skepticism at the result. It will be tested in more detail by other scientists, and eventually, someone will figure it out; they’ll prove or disprove it. That’s how science works. In the meantime, those who believe dark matter is the best explanation for the observable universe will keep looking for the unseen mechanism.

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