Tag Archives: AstraZenecaOxford

Canada hesitates to update guidance on AstraZeneca-Oxford vaccine amid potential link to blood clots

This is an excerpt from Second Opinion, a weekly roundup of health and medical science news emailed to subscribers every Saturday morning. If you haven’t subscribed yet, you can do that by clicking here.


Scientists in Europe have reportedly found a link between the AstraZeneca-Oxford COVID-19 vaccine and extremely rare but potentially fatal blood clots, but Canadian public health officials have so far provided no update on guidance for the shot.

News broke on Friday that researchers in Germany and Norway said they had found a mechanism that could cause the AstraZeneca-Oxford vaccine to create the blood clots in very rare circumstances, in addition to identifying a possible treatment for it.

The finding comes after the European Medicines Agency (EMA) investigated 25 cases of the rare blood clots out of about 20 million AstraZeneca shots given and concluded on Thursday that the benefits from the vaccine far outweigh its possible risks, although a definitive link could not be ruled out.

The EMA said there was no increased risk from blood clots and that because the AstraZeneca-Oxford vaccine is effective in preventing COVID-19, which itself causes blood clots, the shot could actually reduce the risk of them overall.

But not all blood clots are the same, and 18 of the cases in Europe were of an extremely rare type called cerebral venous sinus thrombosis (CVST) — where veins that drain blood from the brain are obstructed and can potentially cause fatal bleeding.

Most of the incidents occurred within 14 days of receiving the AstraZeneca shot, and the majority were in women under the age of 55. It’s worth noting that this type of blood clot is much more common in women, particularly during and after pregnancy and while on birth control.

WATCH | Tam says benefits of AstraZeneca vaccine outweigh risks:

Canada’s Chief Public Health Officer Dr. Theresa Tam says the benefits of the AstraZeneca COVID-19 vaccine outweigh the rare risks. 1:53

Three of the seven patients in Germany who were recently vaccinated with the AstraZeneca-Oxford shot that had this rare brain blood clot have died.

In its investigative document, the EMA said it would expect to see just 1.35 cases of CVST in the time period it looked at — but instead its researchers saw 12.

Germany and Italy resumed vaccinations with the shot on Friday, but France opted to vaccinate only those over 55 with the AstraZeneca vaccine after discovering three cases of CVST. Denmark, Sweden and Norway decided to hold off on using the vaccine until at least next week, citing the need for more time to investigate.

Findings ‘need to be investigated’

“You cannot brush adverse effects under the rug. They always need to be investigated, and I think we have to look at this in a careful and critical manner,” said Dr. Isaac Bogoch, an infectious diseases physician and member of Ontario’s COVID-19 vaccine task force.

“We don’t have all the information yet and we’ll learn more about this — and I imagine we’ll see some updated guidance on who should get this vaccine and perhaps who shouldn’t be getting this vaccine.”

Health Canada released a statement on Thursday saying the benefits of the AstraZeneca-Oxford vaccine outweighed the risks and that the vaccine does not increase the “overall risk of blood clots,” but it provided no update on Friday when pressed for more comment on the evolving situation.

“As the vaccine rollout continues in Canada, Health Canada will continue to monitor the use of all COVID-19 vaccines closely,” the statement read.

“Health Canada will examine and assess any new safety concerns, and should a safety signal be confirmed, the department will take appropriate action.”

Researchers in Norway reported identifying the mechanism early Friday, saying it was due to a “powerful immune response” from the vaccine.


The AstraZeneca vaccine is prepared at the local vaccination centre in Hagen, Germany. Germany and Italy resumed vaccinations with the shot on Friday, the day after the European Medicines Agency found there was no increased risk of blood clots from the vaccine. (Kai Pfaffenbach/Reuters)

German researchers corroborated that finding, adding they had found a typical intravenous immunoglobulin treatment that can be offered to patients in hospitals if this rare type of blood clot occurs, but they said it wouldn’t work as a preventive measure.

“Of course you can’t completely undo a complication,” Dr. Andreas Greinacher, a professor of transfusion medicine at the Greifswald University Clinic, said during a news conference in Germany.

“But at least now we can offer the right treatment to be able to help as quickly as possible and as efficiently as possible.”

Potential blood clot link could alter rollout in Canada

The potential link could have massive implications on the rollout of the vaccine in Canada and other countries, after use of the shot was halted in parts of Europe over safety concerns in connection with the adverse events last week.

Health officials now face the unenviable task of either adjusting the rollout or trying to restore confidence in the shot, at a time when a variant-driven third wave is unfolding and many vulnerable Canadians are vastly underprotected from COVID-19.

The National Advisory Committee on Immunization (NACI) recommended earlier this month that Canadians over 65 not receive the shot, despite emerging evidence from around the world demonstrating its ability to prevent severe COVID-19 in older adults.

But that guidance changed on Tuesday after more real-world data on the vaccine’s effectiveness was reviewed by NACI, and CBC News broke the story revealing documents on the federal government’s plans to allow those 65 and older to receive it.

Experts say that while the guidelines for the vaccine could further change and it may not be recommended for certain age groups in the future, the protection against COVID-19 provided by the AstraZeneca-Oxford shot vastly outweighs the risk of rare adverse events.

That being said, we still don’t have all of the answers, and Canadians need to be aware of potential risks moving forward — however small they may be.

Medical experts in Canada divided over findings

Dr. Michael Hill, a professor of neuroscience at the University of Calgary’s Cumming School of Medicine, said on Friday that while the finding out of Europe is interesting, he remains skeptical of the potential link.

“For now, the case prevalence is such that it could still be a coincidence,” he said. “We just do not know.”

Hill said that as new data emerges, new questions will arise until there is enough evidence to meet the criteria to either confirm or deny a causal link to the vaccine.

WATCH | WHO finds AstraZeneca vaccine safe and effective:

The World Organization’s advisory committee on vaccine saftey says the AstraZeneca COVID-19 vaccine’s benefits outweigh the risks and the shot saves lives. 1:09

“The data will evolve further over time,” he said. “Meanwhile, a very large set of randomized trial data has shown no increased major adverse events with the AstraZeneca vaccine compared to placebo.”

Dr. David Fisman, an epidemiologist at the University of Toronto’s Dalla Lana School of Public Health, said German data offered a “compelling picture” that the rare blood clots were potentially linked to the vaccine in rare cases.

“I find myself in disagreement with Health Canada’s guidance on the use of AstraZeneca,” Fisman said.

“I do think that the use of this vaccine should be suspended in Canada until we have more data. At a minimum, I do not think it should be used in women aged 20 to 50 until we know more.”

Fisman said while the messaging around the AstraZeneca shot would be “challenging,” the continued use of the vaccine in the face of the issue that he believes will become “more apparent” as surveillance increases could erode trust in COVID-19 vaccines.

“I appreciate that this is a sunk cost and is politically difficult. I appreciate that vaccines have become a political football,” he said.

“That said, I think suspension of use of [AstraZeneca-Oxford] will create short-term discomfort but is the right thing to do in the longer term.”


In a statement on Thursday, Health Canada said it ‘will continue to monitor the use of all COVID-19 vaccines closely,’ noting that the benefits of the AstraZeneca-Oxford vaccine outweigh the risks. (Hannibal Hanschke/Reuters)

Dr. David Juurlink, head of clinical pharmacology at Sunnybrook Health Sciences Centre in Toronto, said the rare events may signal a causal link with the vaccine but need to be put in context even if they are confirmed.

“If people are foregoing vaccination — AstraZeneca or otherwise — because of fear of some infinitesimally rare adverse effect, they run the risk of dying,” he said.

“I think it’s probably fair to make the claim that the countries in Europe that went against the advice of their regulator and suspended the use — that may cost some of their citizens in those countries their lives.”


To read the entire Second Opinion newsletter every Saturday morning, subscribe by clicking here.

Let’s block ads! (Why?)

CBC | Health News

EU drug regulator backs AstraZeneca-Oxford COVID-19 vaccine after safety investigation

The EU’s drug watchdog said on Thursday it is still convinced the benefits of the AstraZeneca-Oxford COVID-19 vaccine outweigh the risks following an investigation into reports of blood clotting disorders that prompted more than a dozen nations to suspend its use.

The European Medicines Agency (EMA) director Emer Cooke said the watchdog could not definitively rule out a link between blood clot incidents and the vaccine in its investigation into 30 cases of a rare blood clotting condition.

But she said in a briefing that the “clear” conclusion of the review was that the vaccine’s benefits outweigh the possible risks.

“This is a safe and effective vaccine,” Cooke said.

‘I would be vaccinated tomorrow’

However, she said the agency will update its guidance for patients and health-care professionals to include an explanation about potential risks.

“If it were me, I would be vaccinated tomorrow,” Cooke said.

But the EMA wants “to raise awareness among people who have been vaccinated or are going to be vaccinated about things they should look out for,” she said.

The agency has been under growing pressure to clear up safety concerns after a small number of recent reports about bleeding, blood clots and low platelet counts in people who have received the shot.

The agency’s review covering five million people included 30 cases of unusual blood disorders in people in the European Economic Area (EEA), which links 30 European countries.

Cooke said the EMA is in touch with regulators around the world to keep tabs on possible side-effects of all COVID vaccines.

The EMA’s focus and primary concern has been on cases of blood clots in the brain, a rare, difficult to treat condition called cerebral venous thrombosis (CVT) or a subform known as cerebral venous sinus thrombosis (CVST). 

Countries suspended shots

More than 45 million doses of the AstraZeneca vaccine have been administered across the EEA.

At least 13 European countries, including France, Germany and Italy, have stopped administering the shot pending the review, the latest blow to the bloc’s faltering inoculation campaign.


The vaccination centre at the Erfurt, Germany exhibition centre was deserted on Tuesday. After the suspension of the AstraZeneca COVID-19 vaccine, thousands of appointments were cancelled. (Martin Schutt/dpa/The Associated Press)

Britain’s medicines regulator said on Thursday it was investigating five cases of CVST among people given AstraZeneca’s vaccine but it reaffirmed that the benefits of the shot far outweighed any possible risks.

The World Health Organization also this week reaffirmed its support for the shot.

AstraZeneca has said a review covering more than 17 million people who had received the shots in the EU and Britain had found no evidence of an increased risk of blood clots.

Many governments have said the decision to pause inoculations was made out of an abundance of caution, but experts have warned the political interference could undermine public confidence and hobble the bloc’s slow vaccination campaign as governments struggle to tame more infectious variants.

The bloc’s vaccine rollout has lagged behind campaigns by the United States and former EU member Britain.

WATCH | Inside the race to get COVID-19 vaccines to Canadians:

CBC’s David Cochrane goes inside the processes of vaccine delivery and distribution as well as the challenges to deliver on the promise of at least one shot for every Canadian who wants it by July 1. 4:08

Let’s block ads! (Why?)

CBC | Health News

Should I be worried about the AstraZeneca-Oxford vaccine? Your COVID-19 questions answered

As Canada announced it is recommending the use of the AstraZeneca-Oxford COVID-19 vaccine for those 65 and older, some countries overseas are suspending its use over safety concerns.

More than a dozen countries in the European Union — including its largest members Germany, France and Italy — have halted AstraZeneca inoculations pending the outcome of an investigation by the European Medicines Agency (EMA) into isolated cases of bleeding, blood clots and low platelet counts.

Non-EU countries, such as Indonesia and Congo, have also suspended use of the vaccine.

With such divergent guidance on the vaccine, many are asking if it’s safe.

Here’s what you need to know.

How many people have been affected?

Out of the approximately five million European residents who have received AstraZeneca’s shot, about 30 have experienced “thromboembolic events” — clots forming in blood vessels — and a very small number of deaths have been reported.

Denmark was the first country to halt its use of the AstraZeneca vaccine last week after reports of blood clots in some people, including one person who developed multiple clots and died 10 days after receiving at least one dose.

Danish health authorities said the suspension would last for at least two weeks while the cases were investigated, even as they noted that “it cannot be concluded whether there is a link between the vaccine and the blood clots.”


A medical worker prepares an AstraZeneca vaccine shot in Copenhagen, Denmark, on Feb. 11. Denmark was the first country to halt its use of the AstraZeneca vaccine last week after reports of blood clots in some people. (Liselotte Sabroe/Ritzau Scanpix/AFP via Getty Images)

Norway soon followed suit after authorities reported that four people under the age of 50 who had gotten the AstraZeneca vaccine had an unusually low number of blood platelets, which could lead to severe bleeding.

In Britain, where 11 million doses of the AstraZeneca vaccine have been administered — more than any other country — there have been reports of about 11 people who developed blood clots after getting a shot.

Is there proof the vaccine is responsible?

No.

The EMA says there is “no indication that vaccination has caused these conditions.”

The EU regulator said its investigation was continuing and was conducting a “rigorous analysis” of all data, adding that while its review was ongoing, the benefits of the AstraZeneca vaccine outweighed the potential side-effects.

WATCH | EMA sees ‘no indication’ COVID-19 vaccine caused blood clots:

The European Medicines Agency is investigating whether there is a causal link between AstraZeneca’s COVID-19 vaccine and a small number of instances of blood clots. But at this point, it believes the vaccine is safe. 1:31

EMA executive director Emer Cooke said it was carrying out a case-by-case evaluation of incidents and was expected to complete a review on Thursday.

AstraZeneca Plc on Sunday said it had conducted a review of people vaccinated with its COVID-19 vaccine, and no evidence has been found of an increased risk of blood clots. The review covered more than 17 million people vaccinated in the European Union and United Kingdom.

The World Health Organization (WHO) and EMA have joined AstraZeneca in saying there is no proven link.

If not the vaccine, what else could be the cause?

Some doctors pointed out that since vaccination campaigns started by giving doses to the most vulnerable people, those now being immunized are more likely to already have health problems.

Others, such as Dr. Lynora Saxinger — an infectious disease expert at the University of Alberta in Edmonton — said cases of adverse effects are increasing because so many people are now getting vaccinated.

Saxinger also noted that blood clots are fairly common, so investigators will look at overall numbers of people who received the AstraZeneca vaccine compared with those who reported the condition.

“There’s so many people receiving vaccines daily that any health event that happens to anyone around the time they get their shot may or may not be related,” Saxinger told The Canadian Press.

Why did countries stop using the vaccine?

Any time vaccines are rolled out widely, scientists expect some serious health issues and deaths to be reported — simply because millions of people are receiving the shots, and problems would be expected to occur randomly in a group so large.

The vast majority of these end up not being connected to the vaccine, but because COVID-19 vaccines are still experimental and there is no long-term data, scientists must investigate every possibility that the shot could have unforeseen side-effects.

WATCH | No evidence AstraZeneca vaccine causes harm, epidemiologist says:

Despite millions of AstraZeneca-Oxford COVID-19 vaccinations in Europe, there is no evidence of harm from the doses there, says Dr. Christopher Labos, a cardiologist with a degree in epidemiology. 6:01

Governments say they acted out of an abundance of caution when suspending the use of the AstraZeneca vaccine, with German Health Minister Jens Spahn stating on Monday that the decision was not political but based on expert advice.

WHO’s chief scientist, Dr. Soumya Swaminathan, said officials at the United Nations health agency “don’t want people to panic” amid the reports. She noted that of the 300 million doses of coronavirus vaccines that have been given to people globally, “there is no documented death that has been linked to a COVID vaccine.”

Should Canadians be worried?

Prime Minister Justin Trudeau said the AstraZeneca-Oxford COVID-19 vaccine is safe, and Canadians should have no concerns about receiving it. Regulators are “following what has been happening with a specific batch used in Europe,” he said.

Some vaccinologists point to a possible contamination of a certain batch of the vaccine as a potential explanation for the blood clots, but Trudeau said that none of the AstraZeneca doses deployed in Canada have come from the batch that’s under scrutiny in Europe.

WATCH | Health Canada is monitoring Europe’s investigation of AstraZeneca vaccine:

Marc Berthiaume, director of the bureau of medical sciences at Health Canada, says the department is monitoring Europe’s investigation into adverse effects experienced by some people after receiving the AstraZeneca vaccine. 1:54

All of Canada’s current supply is manufactured by the Serum Institute of India, which secured separate regulatory approvals from Health Canada.

That version, which is biologically identical to the AstraZeneca shot but is manufactured under different conditions, has been branded “Covishield.”

Health Canada, which approved AstraZeneca for use on Feb. 23, said there is “no indication” the vaccine causes blood clots, and no adverse events from AstraZeneca doses have been reported in Canada so far.

Are there concerns with other vaccines?

The EMA is currently examining whether COVID-19 shots made by Pfizer-BioNTech, Moderna Inc. and AstraZeneca might be causing low levels of blood platelets in some patients, a condition that could lead to bruising and bleeding.

Data from Health Canada shows 0.085 per cent of doses administered in the country from mid-December to March 5 resulted in an adverse reaction, with 0.009 per cent considered serious. Pain, redness and swelling at the vaccination site were the most common effects.

Most of those doses would have been mRNA vaccines (such as Pfizer and Moderna), which are generally eliciting stronger reactions than the viral vector jabs (such as AstraZeneca).


A health worker administers a COVID-19 vaccine in Montreal on Monday. (Andrej Ivanov/Reuters)

Additionally, experts say that side-effects from vaccines may actually be a sign that they’re working.

“If you have a vaccine that doesn’t produce a reaction in people, the resulting immune response is weaker,” Earl Brown, a microbiologist at the University of Ottawa, said in an interview with The Canadian Press.

Brown said vaccines work by stimulating our immune cells to grow and communicate with each other, giving directions on where to set up for an impending attack by the virus. That results in inflammation, with some of those cells travelling to lymph nodes and causing swelling.

Let’s block ads! (Why?)

CBC | Health News

Canada will recommend AstraZeneca-Oxford vaccine for those over 65, documents show

Canada will change its guidelines on the AstraZeneca-Oxford COVID-19 vaccine and recommend it be given to those over age 65, according to documents obtained by CBC News and sources with direct knowledge of the guidelines.

The National Advisory Committee on Immunization (NACI) previously recommended Canadians over 65 not receive an AstraZeneca-Oxford shot earlier this month, despite emerging evidence from around the world demonstrating its ability to prevent severe COVID-19 in older adults.

But the NACI recommendations were based largely on AstraZeneca-Oxford’s clinical trial data and didn’t examine real-world evidence past Dec. 7 — months before the effectiveness of the vaccine was fully realized in other countries for older age groups.

Those recommendations led provinces to reorganize their vaccination plans for seniors and meant those aged 60-64 could receive the shots ahead of older age groups, who are at greater risk of hospitalization and death from COVID-19.

Sources with firsthand knowledge of the new recommendations confirmed to CBC News that NACI plans to update its guidelines on the vaccine Tuesday. 

Documents obtained by CBC News — marked “final” and dated Tuesday, but which may be subject to change — show the decision is based on emerging real-world data from other countries. The recommendations also state that mRNA vaccines, such as those from Pfizer-BioNTech and Moderna, will still be “prioritized” for older age groups. 

“Following this careful review, NACI decided to expand recommendations for the use of the AstraZeneca-Oxford vaccine to include those 65 years of age and over,” the documents read. 


Pharmacist Abraam Rafael administers a COVID-19 vaccine to Maureen Doyle at his pharmacy in Toronto on Sunday. (Cole Burston/The Canadian Press)

The documents state real-world data of vaccine effectiveness — for those over 65 who received one dose of AstraZeneca’s — saw a “reduction in the risk of symptomatic disease and hospitalization” that appeared to reach a “comparable level” to those aged 18 to 64.

CBC News reached out to representatives from NACI, Health Canada and the Public Health Agency of Canada for comment but did not receive a response by publication time.

No evidence

Other countries such as France and Germany initially advised those 65 and older not to receive the shot, but overturned their decisions earlier this month after new evidence showed the vaccine significantly reduced hospitalizations in that age group.

But Germany followed other European countries like Denmark and Norway on Monday and suspended the use of the AstraZeneca-Oxford shot over reports of blood clotting in some recipients of the vaccine. Italy and France did the same. 

WATCH | Benefits outweigh risks with AstraZeneca vaccine, experts say:

Despite some European countries temporarily halting use of the AstraZeneca-Oxford vaccine after 30 cases of blood clots, experts maintain it is still safe to use in Canada. 2:01

AstraZeneca-Oxford said Sunday a “careful review” of all available safety data for more than 17 million people vaccinated in the European Union and the U.K. showed “no evidence of an increased risk” of blood clots. 

It’s unclear if NACI’s guidelines for the vaccine will change further in light of the blood clotting reports, but the documents make no mention of them and there is no evidence to suggest Canada will follow suit in suspending the use of the shot. 

Prime Minister Justin Trudeau said Monday the AstraZeneca-Oxford vaccine is safe and Canadians should have no concerns about receiving it.

Already hesitant

It’s unclear how the change in recommendations will affect provincial and territorial vaccine rollout plans, given that those aged 60-64 have already started receiving shots and continue to be booked for appointments. 

Quebec is the only province so far to ignore the national recommendations. Officials there said last week they would administer the AstraZeneca-Oxford vaccine to seniors.

Dr. Zain Chagla, an infectious diseases physician and medical director of infection control at St. Joseph’s Healthcare Hamilton, said the vaccine has already raised concerns from the public because the clinical trials underestimated its effectiveness, did not enroll enough people over 65 and lacked key data because few participants actually got infected with COVID-19. 

“People are already hesitant around this vaccine from that,” he said. “And even if you do get better data to support its use you now still have to fight against these three different streams of negativity towards this vaccine.” 

Dr. Nathan Stall, a geriatrician at Mount Sinai Hospital in Toronto, said issues with data from Scotland, regarding the effectiveness of the vaccine in older age groups, may have factored into NACI’s initial decision. 

“Overall, what has happened with the AstraZeneca vaccine has been very, very unfortunate from almost the get-go,” said Stall, who is a member of NACI but does not speak on behalf of the committee. “So many things, unfortunately, went wrong along the way.” 

Stall said the reported blood clotting also “reared its ugly head” at an extremely unfortunate time. 

“Then of course, people see a product that I think they perceive as inferior,” he said. “Secondly, [the initial shipment] expires on April 2, so people feel like this is sort of like this second rate product that’s imminently expiring that the government is trying to get rid of.” 

Stall said all of those factors combined have led to a “very, very understandable but unfortunate perception” that AstraZeneca-Oxford’s is somehow a “bad vaccine” — which simply isn’t true. 

WATCH | Blood clots likely unrelated to vaccine, epidemiologist says:

People who got blood clots after taking the AstraZeneca-Oxford COVID-19 vaccine probably would have gotten them anyway, says epidemiologist and cardiologist Dr. Christopher Labos. He says blood clots are a common ailment among people who are currently the focus of many vaccine programs. 4:01

“I do believe that probably when all is said and done, that the AstraZeneca vaccine is going to show similar real world efficacy in terms of preventing those outcomes we care most about, the hospitalizations and deaths, very comparably to the mRNA vaccines,” he said. 

Matthew Miller, an associate professor of infectious diseases and immunology at McMaster University in Hamilton, said the emergence of real-world data allows officials to continually assess how effective the vaccine is globally.

“That data is now very strongly suggesting that the vaccine is working in those older individuals, and is particularly good at preventing severe infection and hospitalization, which are ultimately the outcomes that are most important,” said Miller, who also works with NACI.

“What we don’t want to have happen is these individuals, especially those who belong to vulnerable demographics, becoming seriously ill, hospitalized and dying. Those are the things that stretch ICU capacity and so those are the outcomes of greatest concern.”

Chagla says clear, transparent communication from politicians and public health officials is needed in order to explain to Canadians why the change was made. 

“It wasn’t the fact that it was ineffective, it was the fact that there just wasn’t data — but there is now,” he said. 

“There is going to be a stigma done by this but at least if people have the right information to make an educated decision and feel like their public health officials are being open and transparent with them, it at least encourages people to make the decision that they need to.”

Let’s block ads! (Why?)

CBC | Health News

Britain approves use of AstraZeneca-Oxford COVID-19 vaccine

Britain on Wednesday became the first country to authorize an easy-to-handle COVID-19 vaccine whose developers hope it will become the “vaccine for the world.” The approval and a shift in policy that will speed up rollout of the vaccine in the United Kingdom comes as a surge in infections threatens to swamp British hospitals.

The Department of Health said it had accepted a recommendation from the Medicines and Healthcare products Regulatory Agency to authorize emergency use of the vaccine developed by Oxford University and U.K.-based drugmaker AstraZeneca.

“The rollout will start on Jan. 4 and will really accelerate into the first few weeks of next year,” British Health Secretary Matt Hancock told Sky News. Britain has bought 100 million doses of the vaccine.

AstraZeneca CEO Pascal Soriot told BBC Radio 4 the company could start shipping the first doses of the vaccine Wednesday or Thursday “and the vaccination will start next week, and we will get to one million — and beyond that — a week, very rapidly.”

Hundreds of thousands of people in the U.K. have already received a different vaccine, made by U.S. drugmaker Pfizer and German firm BioNTech.

Soriot said it was “an important day for millions of people in the U.K. who will get access to this new vaccine. It has been shown to be effective, well-tolerated, simple to administer and is supplied by AstraZeneca at no profit.”


A paramedic opens the doors of an ambulance parked outside Guy’s Hospital in London on Tuesday as rising COVID-19 case numbers put further pressure on the state-run National Health Service during its busiest winter period. (Tolga Akmen/AFP/Getty Images)

Coronavirus vaccines have typically been given in two doses, with an initial shot followed by a booster about three weeks later.

But in a change of approach, the British government said that with the AstraZeneca vaccine it would prioritize giving as many people as possible a single dose, which is believed to give a large measure of protection against the virus. It said people at the highest risk would get priority, and everyone would get a second jab within 12 weeks of the first.

Canada, which has signed agreements to procure a range of vaccine candidates, has a deal with AstraZeneca for 20 million doses.

In a statement released Wednesday after the authorization in the U.K., Health Canada said it has been reviewing AstraZeneca’s vaccine since Oct. 1 and is assessing data “as it becomes available from the manufacturer.”

“There is still information and data to be provided by AstraZeneca for review,” the statement said, adding that the department is “working closely” with international regulators.

Health Canada reiterated that it is working to give Canadians access to vaccines “as quickly as possible without compromising … safety, efficacy and quality standards” but said it can’t provide a timeline for the completion of its review of the AstraZeneca-Oxford vaccine.

Health Canada has so far authorized two vaccines, the messenger RNA vaccines from Pfizer-BioNTech and Moderna Inc.

Climbing case numbers

The new strategy comes against a backdrop of soaring infections in the U.K. The number of hospitalized COVID-19 patients has surpassed the first peak of the outbreak in the spring, with authorities blaming a new, more transmissible variant of the virus, first identified in southeast England, for the spike.

Oxford University’s Dr. Andrew Pollard, one of the leaders of the development team, offered hope the newly approved vaccine will help.

“At the moment, there’s no evidence that the vaccines won’t work against the new variant,” Pollard told Radio 4. “But that is something which we have to look at. We can’t be complacent about this variant or perhaps future variants.”

Partial results from studies in almost 24,000 people in Britain, Brazil and South Africa suggest the shots are safe and about 70 per cent effective for preventing illness from coronavirus infection. That’s not as good as some other vaccine candidates, but Soriot recently told the Sunday Times newspaper that he was confident the vaccine would prove as effective as its rivals.


The AstraZeneca-Oxford vaccine is expected to be relied on in many countries because of its low cost, availability and ease of use. It can be kept in refrigerators rather than the ultra-cold storage some other vaccines require. The company has said it will sell it for $ 2.50 a dose and plans to make up to three billion doses by the end of 2021.

“We have a vaccine for the world,” said Pollard.

Questions remain

Researchers claim the vaccine protected against disease in 62 per cent of those given two full doses and in 90 per cent of those initially given a half dose because of a manufacturing error. However, the second group included only 2,741 people — too few to be conclusive.

Questions also remain about how well the vaccine protects older people. Only 12 per cent of study participants were over 55 and they were enrolled later, so there hasn’t been enough time to see whether they develop infections at a lower rate than those not given the vaccine.

Researchers also were criticized for lack of information in September, when studies were suspended because a participant suffered a serious illness. AstraZeneca initially declined to provide further details due to patient confidentiality.

Ultimately, the trials resumed after regulators reviewed safety data and decided it was safe to continue. Published partial results show no hospitalizations or severe disease among those who received the vaccine. A separate study testing the AstraZeneca vaccine in the United States also is underway.

The vaccine will become the second COVID-19 vaccine in use in Britain. On Dec. 2, regulators gave emergency authorization to the Pfizer-BioNTech vaccine.

Having another vaccine available means that more people can get protection, said Sarah Gilbert, an Oxford scientist involved in the AstraZeneca project. It takes a different approach than the Pfizer-BioNTech one or another developed in the U.S. from Moderna Inc.

The ultra-cold storage those other vaccines need is “very impractical” in developing countries, said Dr. Gillies O’Bryan-Tear, chair of policy and communications for Britain’s Faculty of Pharmaceutical Medicine. It means the AstraZeneca one “may reach more parts of the world than the Pfizer one,” he said.

Britain’s action likely means the World Health Organization will soon clear the AstraZeneca vaccine for use in a global effort to help poor countries called COVAX. The initiative, led by WHO and the vaccines alliance, GAVI, has secured access to at least 100 million doses of the vaccine, with options and other deals to buy more. But none can be distributed until green-lighted by WHO.

The UN health agency does not licence or regulate vaccines itself but typically evaluates vaccines once they have been approved by an agency, such as the U.K. regulator or the European Medicines Agency. WHO experts conduct their own evaluation of whether or not the risks of a vaccine outweigh its benefits and then make a recommendation for the shots to be “pre-qualified” so they can be bought by donors for developing countries.

Most coronavirus vaccines to be used in poorer countries likely will be made by the Serum Institute of India, which has been contracted by AstraZeneca to make one billion doses. In June, the pharmaceutical company announced that the Serum Institute would produce 400 million doses by the end of 2020, but as of early December, only about 50 million doses had been manufactured after production was halted several times.

In addition to the Serum Institute, AstraZeneca also has deals with vaccine makers in Brazil, South Africa and China to make the Oxford-developed vaccine for use in developing countries.

Let’s block ads! (Why?)

CBC | Health News