Context:
AstraZeneca, the manufacturer of the Covishield vaccine for the Covid-19 pandemic, has admitted that the inoculation carries potential side effects. This admission was made in a legal document presented before the High Court of Justice in London. The document conveys that the Covid vaccine can, in extremely rare cases, induce Thrombosis with Thrombocytopenia Syndrome (TTS).
Relevance:
GS II: Health
Dimensions of the Article:
- AstraZeneca’s Position on Thrombosis with Thrombocytopenia Syndrome (TTS)
- Covishield: An Overview
- Thrombosis with Thrombocytopenia Syndrome (TTS)
AstraZeneca’s Position on Thrombosis with Thrombocytopenia Syndrome (TTS)
- AstraZeneca’s statements regarding Thrombosis with Thrombocytopenia Syndrome (TTS) were made in court documents filed in the United Kingdom in response to a lawsuit against the company. Here’s a summary of their remarks:
- AstraZeneca is facing legal action over health claims related to the vaccine it developed with the University of Oxford during the Covid-19 pandemic in 2020.
- In the court documents, AstraZeneca denied that TTS is caused by the vaccine on a broad scale.
- However, the company acknowledged the possibility of TTS occurring as a result of its vaccination, albeit in “very rare cases.”
Covishield: An Overview
Development and Production
- Developed by AstraZeneca in collaboration with the University of Oxford.
- In India, marketed under the brand name Covishield, manufactured by the Serum Institute of India (SII) in Pune.
Administration in India
- Vaccination commenced in India on January 16, 2021.
- Notable observations:
- Indian government issued a caution regarding its administration in individuals with thrombocytopenia.
- Thromboembolic events reported at a rate of 0.61 cases per million doses.
- Covishield continues to have a positive benefit-risk profile according to the Union Health Ministry.
International Concerns and WHO Observations
- European countries temporarily paused the use of AstraZeneca vaccine due to reported cases of blood clotting.
- World Health Organization (WHO) noted cases of Thrombosis with Thrombocytopenia Syndrome (TTS) post-Covishield vaccinations.
- WHO stated that while TTS risk with Covishield vaccines appears low based on available data.
Thrombosis with Thrombocytopenia Syndrome (TTS)
Definition and Characteristics
- Rare condition characterized by blood clot formation (thrombosis) and low platelet counts (thrombocytopenia).
- Associated with certain COVID-19 vaccines, particularly those using adenovirus vectors like Covishield.
- Adenovirus vectors are non-enveloped, double-stranded DNA Virus that are commonly used for gene therapy, vaccination, and cancer gene therapy.
- They are considered the most efficient gene delivery vehicles due to their safety profile and expression.
Mechanism and Hypotheses
- Mechanism not fully understood but hypothesized to involve vaccine-triggered immune response leading to platelet activation and clot formation.
- Resembles autoimmune heparin-induced thrombocytopenia, involving heparin-triggered immune response.
Symptoms and Complications
- Symptoms include breathlessness, chest or limb pain, skin bruising beyond the injection site, headaches, numbness, etc.
- Complications depend on clot location, including stroke, heart attack, and respiratory issues.
Risk Factors
- Factors predisposing individuals to TTS include age, gender (more common in younger women), and potentially genetic factors.
-Source: Indian Express, The Hindu
