AstraZeneca Confirms Rare Side Effect of Covishield: Know More about This Condition

The Telegraph reports that AstraZeneca, the manufacturer of the Covishield vaccine, has for the first time acknowledged in court documents that the vaccine could potentially cause a rare side effect. The company stated, “The AZ vaccine can, in very rare instances, cause TTS. The causal mechanism remains unknown.” This significant admission could result in a substantial legal settlement.

The report indicates that AstraZeneca is facing a class-action lawsuit over allegations that its vaccine can cause a medical condition known as Thrombosis with Thrombocytopenia Syndrome (TTS). This condition results in blood clot formation and a reduction in blood platelet count. Covishield, developed by AstraZeneca and Oxford University, was extensively administered during the COVID-19 pandemic, including in India where it was manufactured by the Serum Institute.

What is TTS? 

 Thrombosis with Thrombocytopenia Syndrome (TTS) is a rare condition characterized by blood clot formation in blood vessels and a reduced number of blood platelets (thrombocytopenia). It has been observed as an extremely rare adverse effect associated with certain COVID-19 vaccines, particularly those that use adenovirus vectors, like the AstraZeneca vaccine (Covishield).

The precise mechanism by which TTS occurs following Covishield vaccination is not fully understood. However, a doctor suggests that the vaccine may initiate an immune response leading to platelet activation and blood clot formation, similar to autoimmune heparin-induced thrombocytopenia.

“This is different from non-vaccine related thrombosis where factors such as surgery, smoking, or obesity might trigger thrombosis without the immune-mediated platelet activation seen in TTS,” he adds.

Who is at risk? 

While TTS is extremely rare, certain factors such as age, gender (more common in younger women), and possibly genetic factors might predispose individuals to this condition.

Healthcare providers are urged to monitor for TTS symptoms, particularly in those at higher risk, to ensure prompt management and treatment of the condition. TTS typically manifests as severe headache, blurred vision, chest pain, leg swelling, persistent abdominal pain, and shortness of breath within a few weeks after vaccination.

Early detection and treatment are key to recovery, hence healthcare providers and patients are advised to be alert for these symptoms.

Implications of AstraZeneca’s admission for vaccine safety monitoring and regulatory practices a doctor believes that AstraZeneca’s acknowledgment of the link between Covishield and TTS could lead to enhanced safety monitoring and regulatory scrutiny for vaccines.

He suggests that this development might affect public trust in vaccines, underlining the importance of transparent communication and robust vaccine surveillance systems to maintain public faith in global vaccination programs.

Should Indians be concerned? 

A doctor assures that while Indians should be aware of this report, there is no need for alarm.

“Considering the rarity of TTS, the benefits of the Covishield vaccine in preventing COVID-19, which can have severe consequences, generally outweigh the risks of this rare side effect,” he clarifies.

He recommends continuous monitoring and immediate medical attention for symptoms as strategies for managing the risk.