Khaberni - An international team of researchers has finally revealed the scientific reason behind the rare blood clots that appeared in some recipients of adenovirus-based Corona vaccines.
Since the emergence of Corona vaccines, very rare cases of individuals suffering from serious blood clots after receiving some vaccines were recorded, but no one was able to accurately explain the reason.
Today, researchers from Canada, Australia, and Germany have uncovered the mechanism that leads to these rare clots, and it turns out that the problem begins with a simple yet catastrophic mistake made by the immune system.
In very rare cases, the immune system mistakenly identifies its target, attacking the body's cells instead of defending them.
The new study details how sometimes the body can produce harmful antibodies that attack normal blood proteins, leading to a condition known as "vaccine-induced immune thrombotic thrombocytopenia." The research team was able to identify the exact viral component responsible for triggering this response.
How does the problem occur?
Imagine that your immune system is an army trained to protect the body from enemies. When an adenovirus enters the body, whether through natural infection or via the vaccine, this army begins producing special weapons called "antibodies" to combat a specific protein in the virus called "protein VII".
The problem is that this viral protein closely resembles a natural human protein called "platelet factor 4". In the vast majority of people, this similarity does not cause any problems, because the immune system precisely distinguishes the difference.
However, in very rare cases, and during the battle between the immune system and the virus, a simple genetic mutation occurs in one of the antibody-producing cells. This mutation changes just one amino acid out of thousands that make up this cell.
Despite its simplicity, this small change is enough to redirect the focus of the antibody from the viral protein to the human protein.
When this mutated antibody binds to the human protein, it abnormally activates the platelets, leading to blood clotting and at the same time, a reduction in the number of platelets, which is the distinctive feature of this rare condition.
Most importantly, the researchers found the exact same mutation in all the antibodies they analyzed from patients who suffered from these clots. They did not stop there but engineered antibodies in the lab and reversed this mutation, completely eliminating its ability to cause clotting. This is conclusive evidence that this mutation is the main reason behind this condition.
Theodore Warkentin, Honorary Professor at McMaster University in Canada and the lead author of the study, says: "This discovery accurately shows at the molecular level how a normal immune response can deviate in very rare cases. For the first time, we not only understand what is happening, but we understand why it is happening."
