Explained: What's TTS, rare condition caused by AstraZeneca's Covishield vaccine
In a significant development, AstraZeneca, the manufacturer of the Covishield vaccine, has acknowledged in legal documents that its vaccine may trigger a rare side effect known as Thrombosis with Thrombocytopenia Syndrome (TTS). The company is currently facing a class action lawsuit over claims that its vaccine can cause TTS, an infrequent condition characterized by blood clot formation and a decrease in blood platelets. Here's what we know about the rare side effect.
Potential causes and risk factors of TTS
Public health expert Dr. Jagadish J Hiremath suggests that the Covishield vaccine might trigger an immune response leading to platelet activation and blood clot formation, similar to autoimmune heparin-induced thrombocytopenia. This differs from non-vaccine related thrombosis where factors like surgery, smoking, or obesity can cause thrombosis without the immune-mediated platelet activation seen in TTS. Certain factors such as age, gender (more common in younger women), and potential genetic elements may increase susceptibility to this condition.
Covishield widely used in India during pandemic
To recall, Covishield, developed by AstraZeneca and Oxford University, was widely used during the COVID-19 pandemic, including in India where it was produced by the Serum Institute.
Recognizing and managing TTS symptoms post-vaccination
Amid the row, healthcare providers are advised to monitor for symptoms of TTS, particularly in those more at risk, Hiremath said. Symptoms typically include severe headache, blurred vision, chest pain, leg swelling, persistent abdominal pain, and shortness of breath appearing within weeks after vaccination. Indians need to be aware but not necessarily alarmed about this report, he explained. He advocated for continuous monitoring and immediate medical attention for symptoms as strategies to manage this risk.
AstraZeneca's acknowledgment may improve safety monitoring
Hiremath added, "AstraZeneca's acknowledgment of the link between Covishield and TTS may prompt enhanced safety monitoring and regulatory oversight for vaccines." This development, he said, might affect public trust in vaccines, emphasising the need for transparent communication and robust vaccine surveillance systems to maintain public confidence in vaccination programs worldwide.
