A health professional holds a box of AstraZeneneca vaccine at the Institute of Infectious Diseases in Bamrasnaradura, in the province of Nonthaburi, just outside Bangkok.
Chaiwat Subprasom | SOPA images | LightRocket via Getty Images
LONDON – The coronavirus vaccine developed by AstraZeneca and the University of Oxford has been suspended in several countries in Europe and Asia, after reports of blood clots in some vaccinated people. Many other nations, however, have defended the use of the vaccine and said they will continue with their respective vaccination campaigns.
On Friday, Thailand became the first Asian country to stop using the jab for security reasons, shortly after Denmark announced a two-week break from its national launch after reports of blood clots and a death.
In a setback for Europe’s vaccination campaign, seven other countries have also suspended the use of the Oxford-AstraZeneca injection: Norway, Iceland, Bulgaria, Luxembourg, Estonia, Lithuania and Latvia.
Austria and Italy, for their part, said they would stop using certain batches of the vaccine as a precautionary measure.
Europe’s drug regulatory agency, the European Medicines Agency, emphasized on Thursday that there was no indication that the injection was causing blood clots, adding that it believes the vaccine’s benefits “continue to outweigh its risks”.
The EMA acknowledged that some member states have discontinued the use of the Oxford-AstraZeneca injection, but said that inoculations can continue to be administered as long as an investigation of blood clot cases is ongoing.
As of Wednesday, around 5 million people in Europe had received the Oxford-AstraZeneca vaccine. Of that number, 30 cases of so-called “thromboembolic events” have been reported. These cases refer to the formation of blood clots in the blood vessels and blockage of blood flow.
AstraZeneca said the vaccine was studied extensively during Phase 3 tests and peer-reviewed data confirm that the injection is “generally well tolerated”.
Why are countries pausing vaccination campaigns?
Thailand’s health ministry announced on Friday that it would temporarily postpone the use of the Oxford-AstraZeneca vaccine, allegedly describing the vaccine as a “good vaccine”, but which it wants to suspend for safety investigations.
Kiattiphum Wongjit, permanent secretary of the Ministry of Public Health, said the Southeast Asian country was able to stop its vaccination campaign because it largely brought a second wave of Covid cases under control through quarantines and border controls, according to Reuters.
A press conference on the temporary suspension of the implementation of the AstraZeneca Covid-19 vaccination in Thailand will be held in Bangkok, Thailand, on March 12, 2021.
Xinhua | Rachen Sageamsak via Getty Images
The country of nearly 70 million people has so far registered about 26,600 cases and 85 deaths, according to data compiled by Johns Hopkins University.
Thailand’s decision to halt the planned launch of the Oxford-AstraZeneca vaccine, which was due to start on Friday, came after the decision of the Danish Health Authority.
“It is important to emphasize that we have not opted for the AstraZeneca vaccine, but we are suspending it,” said Soren Brostrom, director of the National Health Council of Denmark, on Thursday.
“There is good evidence that the vaccine is safe and effective. But both we and the Danish Medicines Agency have to react to reports of possible serious side effects, both from Denmark and other European countries.”
Many high-income countries have chosen to continue distributing the Oxford-AstraZeneca vaccine because of safety concerns.
The United Kingdom, France, Australia, Canada and Mexico are among some of the nations that have sought to reassure citizens about the benefits of receiving the vaccine and said they will continue with their respective vaccination campaigns.
What do the experts say?
The EMA safety committee is looking into the matter, but said there is currently no evidence that vaccination has caused blood clots – noting that they are not listed as side effects of this vaccine.
The European drug regulator also noted that the data available so far shows that the number of blood clots in vaccinated people is not greater than that seen in the general population.
“Blood clot reports received so far are no greater than the number that would have occurred naturally in the vaccinated population,” said Dr. Phil Bryan, vaccine safety leader at the UK’s Medicines and Health Products Regulatory.
“Public safety will always come first. We are keeping this subject under review, but the available evidence does not confirm that the vaccine is the cause. People should still get their COVID-19 vaccine when asked to do so.” Bryan said.
Resident of Southampton, Peter Brownsea receives the Oxford / AstraZeneca Covid-19 vaccine from a member of the Hampshire Fire and Rescue Service at a temporary vaccination center installed at the Fire Department in Basingstoke, Hampshire, southern England, while the teams continue answering 999 emergency calls.
Andrew Matthews | AFP | Getty Images
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said: “The problem with spontaneous reports of suspected adverse reactions to a vaccine is the enormous difficulty in distinguishing a causal effect from a coincidence.”
“This is especially true when we know that Covid-19 disease is strongly associated with blood clotting and there have been hundreds, if not many thousands of deaths caused by blood clotting as a result of Covid-19 disease. The first thing to do is to be absolutely sure that the clots had no other cause, including Covid-19, “added Evans.
How does the vaccine work?
The Oxford-AstraZeneca vaccine is an injection designed to prevent the coronavirus in people aged 18 and over. It consists of an adenovirus that has been modified to contain the gene for the production of a SARS-CoV-2 protein, the virus that causes Covid-19.
The most common side effects of the vaccine, which does not contain the virus and cannot cause Covid, are usually mild or moderate and improve a few days after vaccination.
Final-stage clinical trials found that the AstraZeneca-Oxford injection had an average 70% effectiveness in protecting against the virus.
A more recent study by Oxford researchers found that the Covid vaccine was 76% effective in preventing symptomatic infection for three months after a single dose, and that the rate of effectiveness actually increased with a longer interval between the first and the second. doses.
– CNBC’s Holly Ellyatt contributed to this report.