What is thrombosis, can be a rare side effect of AstraZeneca Covid vaccine

pharmaceutical giant AstraZeneca Admitted to British courts that its COVID-19 vaccine could, in very rare cases, cause Thrombosis with thrombocytopenia syndrome (TTS), The laboratory’s statement took place within the framework of a class action lawsuit in the United Kingdom, publicized by those affected, who allege serious injuries and health damage from the use of the vaccine developed in collaboration with it. University of Oxford.

AstraZeneca had previously reported the possibility of this adverse effect in 2021 through a publication lancet magazine From a study titledVery rare thrombosis with thrombocytopenia after the second dose of AZD1222: an analysis of the global safety database.”, done by scientists from the laboratory itself.

There, he said that “Since the launch of the COVID-19 vaccine, there are reports that Very rare cases of TTSit is known as Vaccine-induced immune thrombotic thrombocytopenia (VITT),

Now, the pharmaceutical giant has once again assured the United Kingdom court that its COVID vaccine shows an acceptable safety profile, which is supported by global regulators who confirm this. The benefits of vaccination outweigh the risks associated with it For extremely rare side effects.

He Thrombosis with thrombocytopenia syndrome (TTS)) involves the formation of Blood clots with low platelet count,

United States National Institutes of Health (NIH) Describe it plateletsalso known as thrombocytesare the cells required for coagulationBecause when a person is injured, clots are responsible for sealing the wounds.

Platelet count increases to less than 150,000 risk Of hemorrhageWhich can appear both internally and on the surface of the skin.

gravity Low platelet count increases bleeding and may potentially fatal, especially if they occur Brain,

Early detection and treatment is important prevent complications Serious illnesses associated with this condition.

Based on the use of the vaccine developed by Oxford University and AstraZeneca adenovirus (specifically a chimpanzee common cold virus). It acts as a modified adenovirus vehicle to carry antigen Without causing disease in the human body.

A study published in the American Journal science advancement He had already described it in December 2021 Interaction between the surface of the adenovirus used in the vaccine and platelet factor 4 (PF4) present in human blood In rare cases, it may cause wrong immune response,

In some rare cases, the immune system may mistake PF4 for a virus and release antibodies in response. Antibodies will aggregate with PF4 and will finally give birth blood clots.

Researchers describe process that involves small amounts of adenovirus ChAdOx1 The vaccine enters the bloodstream through small wounds in the capillaries caused by injection. This can lead to the formation of a complex between ChAdOx1 and PF4, potentially triggering clot formation.

It is important to note that this process requires several intermediate steps before clottingThis shows that The mechanism is neither obvious nor inevitable, but the product of an unfortunate and rare series of events. ,

“What we have is the trigger, but there are several steps that need to happen next,” he explained. Professor Alan Parker, one of the researchers at Cardiff University, is in charge of the study published in Science Advances

Following a 2021 investigation, the company noted that, although a possible mechanism, it does not conclusively establish that it is the cause of rare cases of thrombosis. Besides, Emphasized that the presence of PF4 antibodies does not automatically cause the development of clots In most individuals.

And he emphasized that the risk associated with the formation of blood clots in cases of COVID-19 infection is significantly higher than with the administration of any vaccine.

Bleeding is responsible for the main symptoms of Thrombocytopenia, Signs may appear in the body suddenly or as the day goes on, Mild thrombocytopenia usually has no symptoms and is therefore often detected only through routine blood tests.

The United States’ NIH details this Symptoms of Thrombocytopenia may include:

• Bleeding that lasts a long time, even from small wounds
• petechiae, which are small, flat red spots under the skin caused by blood loss from blood vessels
• Purpura, which is bleeding on the skin that can cause red, purple, or yellow-brown spots
• bleeding from the nose or gums
• blood in your urine or stool, which may look like red or dark blood
• heavy menstrual bleeding

“TTS is a serious and potentially fatal adverse event,” he said. World Health Organization (WHO) Their “Guidelines for the management of clinical cases of TTS following vaccination to prevent COVID-19 disease” was updated in April 2023.

scientific study and WHO Global Advisory Committee on Vaccine Safety confirmed the existence of thrombosis syndrome with thrombocytopenia following administration of the AstraZeneca vaccine, although they also highlighted that the events “they are very rare

, The committee said: “A new type of extremely rare adverse event, known as thrombosis syndrome with thrombocytopenia, following administration of this vaccine. This syndrome includes serious and rare blood coagulation disorders associated with low platelet counts.

“In countries where transmission of SARS-CoV-2 is currently recorded, The benefits of vaccination far outweigh the risks. “Given the protection provided by the vaccine against COVID-19,” WHO experts declared.

according to the newspaper WireAdvocate sarah moore, Study partner Leigh Day, who is part of the UK lawsuit, said that “it took a year for AstraZeneca to formally admit that its vaccine could cause devastating blood clots, while this fact was not acknowledged until late 2021.” Has been widely accepted by the clinical field”.

On its part, the pharmacist in a statement said: “Our solidarity is with all those who have lost loved ones or reported health problems. Patient safety is our top priority And regulatory authorities have clear and strict standards to ensure the safe use of all medicines, including vaccines.