Blood Clots after Oxford Vaccine
- December 5, 2021
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Blood Clots after Oxford Vaccine
Subject – Science and Tech
Context – Study finds mechanism of blood clots after giving Oxford vaccine
Concept –
- The journal Science Advances has revealed for the first time the mechanism responsible for blood clots arising from thrombosis with thrombocytopenia syndrome (TTS) following vaccination with AstraZeneca vaccine.
- Thrombocytopenia syndrome causes low platelet count.
- A low number of platelets – blood cells that help prevent blood loss when vessels are damaged – can result in no symptoms or can lead to an increased risk of bleeding or, in some cases, clotting.
- Thrombosis with thrombocytopenia syndrome is a very rare serious adverse effect following vaccination using chimpanzee adenovirus Y25 (ChAdOx1), human adenovirus type 26 (HAdV-D26), and human adenovirus type 5 (HAdV-C5).
- AstraZeneca vaccine and the Indian counterpart Covishield use the chimpanzee adenovirus Y25, while Johnson & Johnson vaccine uses the human adenovirus type 26.
- The Sputnik vaccine uses both human adenovirus type 26 and human adenovirus type 5 as vectors to ferry the spike protein into certain cells.
- The researchers found that all three adenoviruses used in a few COVID-19 vaccines as vectors bind to platelet factor 4 (PF4). They found that adenoviruses form stable complexes with PF4.
What is Thrombosis?
- Thrombosis is the formation of a blood clot, known as a thrombus, within a blood vessel. It prevents blood from flowing normally through the circulatory system.
- Blood clotting, also known as coagulation, is the body’s first line of defense against bleeding. When we hurt ourselves, our clotting system forms a “plug” or “seal” to protect us from losing too much blood.
- Our bodies often break down the clot after we’ve healed – but sometimes, clots form inappropriately or fail to dissolve after an injury. A blood clot that forms and stays in a blood vessel is called a thrombus.
- Other medical terms used to describe blood clots include:
- Thrombosis: When a thrombus forms in a blood vessel.
- Embolus or Embolism: A clot that detaches and travels through blood vessels to another part of the body.