Cerebral venous sinus thombrosis is the condition that terrified regulators by appearing in recipients of the AstraZeneca or Johnson & Johnson shocks.
However, researchers claim that the risk of developing the complication is significantly higher after receiving the coronavirus than after receiving one of the Covid shocks.
The benefits of vaccination are far greater than the risks, they insist, as the chance of getting a clot is still rare and mass vaccination protects millions of people – both those who get the bumps and those around them around.
Oxford University scientists looked at data from the United States to find out the number of times people were diagnosed with CVST after testing positive for coronavirus.
They estimated the rate at 39 cases per million people – 0.0039 percent, or one in 25,641.
The rate for people who had Pfizer or Moderna’s vaccine was four in a million – 0.00039 percent, or one in 250,000.
And based on European data, they said the risk after AstraZeneca’s sting was roughly five in a million – 0.0005 percent, or one in 200,000.
“The key message is that the risk of this particular event is actually much less than if you got Covid or someone else got Covid,” said Dr. John Geddes of the University Biomedical Research Center.
The study comes after another Oxford professor who was not involved in the research, Sir John Bell, said today that the risk of blood clots after vaccination is “trivial”.
The Oxford study calculations suggest that the CVST rate in people who test positive for Covid-19 is 39 in a million, compared to four to five per million after vaccination
The risk of portal vein thrombosis, a type of blood clot in the liver, was also significantly higher after Covid-19 than after vaccination
Experts say the risk of not being vaccinated against Covid is far greater than the risk of getting a sting (Picture: A man who was vaccinated in London yesterday, April 14th).
The study looked at the risk of developing a CVST clot within two weeks of being diagnosed with Covid or flu or taking the Pfizer or Moderna vaccine.
The records were from 500,000 people, most of them in the United States.
No new data has been collected on the AstraZeneca vaccine, which is the main vaccine for drug regulators because it is not used in the US.
The purpose of the study was to determine the risk of CVST after Covid, which is not well understood.
The study found that coagulation rates in people who caught Covid were significantly higher than in people who had been vaccinated.
Pfizer or Moderna bursts, which are based on the same synthetic mRNA technology, had a rate ten times lower than that of the Covid patients.
Data from the European Medicines Agency suggested the risk of AstraZeneca’s sting, which contains a live cold virus, was eight times lower.
They found that, for comparison, no one developed CVST within two weeks of being diagnosed with flu.
WHAT IS CVST?
Cerebral venous sinus thrombosis (CVST) is an extremely rare type of blood clot in the brain.
It can also be abbreviated to CSVT or just CVT – they are basically all the same.
It occurs when the vein that drains blood from the brain becomes blocked by a blood clot, causing potentially fatal bleeding or a stroke.
Symptoms can quickly worsen from headaches, blurred vision, and fainting, to complete loss of control of movement and seizures.
John Hopkins University estimates that it affects five in a million people in the US each year, suggesting that 330 patients in the UK have the disease annually.
According to the university, it may affect patients with low blood pressure, cancer, vascular disease, and those who have a tendency to blood clotting. Head injuries can also trigger the condition.
The UK regulator said CSVT was so rare that they weren’t even sure how common it was in the general population.
CVST is a disease in which a clot develops in a vein leading from the brain that can cause a stroke.
Drug regulators are particularly concerned that this condition develops alongside a decrease in platelets, but researchers didn’t have enough detailed data to specifically study this.
Professor Paul Harrison, psychiatrist and one of the study’s researchers, said, “We have drawn two important conclusions. First, Covid significantly increases the risk of CVT and adds to the list of blood clotting problems that this infection causes.
Second, the risk of Covid-19 is higher than with current vaccines, even in those under the age of 30. This should be taken into account when considering the balance between risk and benefit for vaccination. “
UK drug chiefs have decided to stop offering the AstraZeneca jab to those under 30 as they weren’t sure if their risk of Covid was significantly higher than the risk of the vaccine.
However, this study found that younger age groups were affected far worse after Covid.
Overall, 30 percent of CVST cases were found in people under the age of 30.
This suggests that Covid increases the risk of CVST in younger people – as experts suggest – even if it increases the risk of CVST.
Dr. Max Taquet said in a briefing: “I assume that age will not have any influence.
‘CVT occurs in the age group. There are no more cases of CVT in younger patients. ‘
The team said they had sent the data to Professor Chris Whitty, England’s chief medical officer, and the Joint Committee on Vaccination and Immunization, but added, “It is not our job to make or change guidelines.”
Regarding whether the potential risk of getting a vaccine is worth it for people living in areas with low rates of covid, the researchers insisted that shocks be a top priority.
Dr. Taquet said, “You could live in an area with no Covid cases so you might think you don’t need the vaccine, but to keep it at zero you need people taking the vaccine.”
Professor Harrison added, “We only have evidence that the risks from Covid are far greater than anything else [linked to the vaccine] .
“You may think you won’t catch it, but anyone can get it.”
The researchers said their results should be interpreted with caution as they come from different sources.
The study is published online but has not yet been reviewed by a journal.
Another Oxford professor, Sir John Bell, said on Sky News, “The best way if you want to have a bad clotting problem is to get Covid.
“And if you don’t get a vaccine you will get Covid, and if you do get Covid you are at a very, much higher risk of having a bad clotting problem.
“So the coagulation problems of the vaccine are pretty trivial compared to the actual risks of coagulation problems with Covid.”