The Drugs and Medical Products Regulatory Agency (MHRA) said in a statement that it has received 22 reports of cerebral venous sinus thrombosis (CVST), including clots in the sinuses that drain blood from the brain, and 8 Report on thrombosis. As of March 21, a total of 15.8 million people had received at least one dose of the vaccine. MHRA’s CVST data details show that there were four deaths, but the agency did not immediately respond to CNN’s questions to confirm whether there were any deaths.
But more and more reports of blood clots from different countries are pouring in, especially in Europe, where AstraZeneca vaccine is widely used. Some countries choose to suspend the use of the vaccine altogether, while others restrict its use to certain age groups.
It reads: “The Norwegian Medicines Agency believes that this vaccine may be linked, but we need more research to figure out what caused this vaccine.”
This is something else to know.
How do scientists determine if there is a connection?
One indicator to look at is morbidity. Generally speaking, blood clots are so common that on any given day of the week, a certain number of people will get blood clots for various reasons. If someone is vaccinated and then forms a blood clot, it is not necessarily the blood clot caused by the vaccine.
After the initial report of blood clot formation last month, AstraZeneca quickly pointed out that the overall incidence of blood clots in the people who received injections was lower than the general population in countries where injections were used.
AstraZeneca spokesperson said in a statement issued to CNN on Friday: “Patient safety remains the company’s top priority” and pointed out that the United Kingdom, the European Union and the World Health Organization are concerned. Recommendations to continue using the product.
The spokesperson said: “The monthly safety update of EMA reconfirms the beneficial risks of the vaccine.”
In order to understand the situation more clearly, scientists are studying the types of blood clots reported in more detail. CVST is rare at first, and generally, it is not difficult to determine whether the incidence of blood clot events has increased. However, in this case, it is a bit vague, partly because the incidence of CVST in the population is not clear in the first place.
MHRA said that 15.8 million people in the UK have received at least one dose of AstraZeneca. In 30 cases of CVST or other thrombosis in the UK, the incidence of developing a rare clot was one in a million, which was 1.89.
David Werring of the UCL Institute of Neurology told the Science Media Center: “Therefore, the absolute risk of developing CVST after this vaccine is still very low… and it is not clear whether this is higher than the usual expected CVST. The incidence is high.”
He said that in the UK, the usual incidence of CVST may be about 5 to 15 parts per million per year, but he added that these numbers vary because it is difficult to diagnose certain cases.
The nature of these blood clots has become the focus of attention of scientists. Emerging evidence suggests that certain blood clots after vaccination have abnormal characteristics. EMA and several other health experts in the region pointed out that although these patients have blood clots, they also abnormally exhibit symptoms of thrombocytopenia-the number of platelets is low, which usually prevents clot formation.
Wolin said: “This increases the possibility that this vaccine may be the cause of these rare and unusual CVST cases, although we don’t know yet, so more research is urgently needed.”
Experts have always said that the benefits are greater than the risks, but how much is the benefit?
If you look at this question from a global or even national perspective, the answer is: a lot.
think about it. Since the UK began to vaccinate people on December 7th until March 21st, there have been 30 rare cases of blood clots, of which 4 were fatal. Government data shows that in the same period, more than 2.5 million people caught Covid-19 and 63,082 people died from the virus in the country.
David Spiegelhalter, chairman of the Winton Centre for Risk and Evidence Exchange at the University of Cambridge, said: “It is vital that the introduction of vaccination must be delayed.”
He pointed to a model that shows that even if the current virus levels are low, delays in vaccinating 500,000 people between the ages of 44 and 54 may still result in about 85 hospitalizations and 5 deaths.
However, these dynamics may look different when considering data broken down by gender and age.
Spiegelhalt said: “It is important to know whether this risk is significantly higher among young people than elsewhere. Vaccination among young people is not only beneficial to the wider community, but also directly to them. Therefore, It is reasonable to avoid this situation reasonably. Even if it causes very little harm.”
In general, the health consequences of Covid-19 on the elderly are more serious. But the number of hospitalizations in some parts of Brazil and the United States shows that young people are more likely to get serious illnesses than before. It is not clear whether the new variant is the cause, vaccination level, behavior, or a combination of multiple factors.
Can these blood clots be fatal?
The numbers entered are very small, and it is difficult to draw conclusions about the mortality rate. In Germany, 9 of the 31 CVST cases have died. In the UK, there are four.
Andreas Greinacher of Greifswald University introduced some findings of the team to reporters this week, saying that he thought it was a reaction to the injection of the vaccine “vaccine-induced thrombosis” Immune Thrombocytopenia” or VIPIT. The organization calls on medical experts not to use heparin after AstraZeneca injections in patients with blood clots, because the drug may worsen their condition.