In
the midst of a global pandemic, the race to develop effective COVID-19 vaccines
became a beacon of hope. Among these, Covishield - a vaccine jointly developed
by British pharma giant AstraZeneca and Oxford University- has played a
significant role in India's vaccination drive. However, its journey has been
marked by controversies, legal battles, and concerns over side effects.
58.1 Origin and Development:
Covishield owes its existence to a collaboration between the University of Oxford and British
pharmaceutical major AstraZeneca. The vaccine utilizes a modified
chimpanzee adenovirus called ChAdOx1
as its vector. The development process involved rigorous research, clinical
trials, and regulatory approvals.
The vaccine formula was licensed to SII(Serum Institute of India) during the pandemic, leading to the
production of over 175 crore doses in India. Its rollout promised protection
against COVID-19, but as the vaccination drive progressed, unexpected issues
surfaced.
Studies conducted in 2020 demonstrated that Covishield has an efficacy of 76.0% in preventing symptomatic COVID-19 after the first dose and 81.3% after the second dose.It is stable at refrigerator temperatures and has a good safety profile, with common side effects like injection-site pain, headache, and nausea.
58.2 TTS (Thrombosis Thrombocytopenia Syndrome):
Covishield has faced scrutiny due to rare side effects, including
Thrombosis with Thrombocytopenia Syndrome (TTS). AstraZeneca acknowledged this
connection, emphasizing that TTS occurs in very rare cases.
TTS involves the presence of blood clots
(thrombosis) along with low levels of platelets (thrombocytopenia), which are
crucial for blood clotting.
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Symptoms of TTS:
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Severe or persistent headaches
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Blurred vision
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Shortness of breath
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Chest pain
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Leg swelling
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Persistent abdominal pain
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Easy bruising or tiny blood spots
under the skin beyond the injection site.
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Unusual Clot Locations: TTS often involves
blood clots in unusual locations, such as in the brain (cerebral venous sinus
thrombosis) or abdomen.
The risk of TTS with Covishield appears to be
very low. In the UK, the risk is approximately four cases per million adults
who receive the vaccine, while in the European Union, it’s estimated to be
approximately one case per 100,000.
58.3 Supreme Court Petition:
●
On May 1, 2024, a petition was filed in the
Supreme Court of India seeking the constitution of an expert medical panel to
study the risk factors associated with the Covishield vaccine. The petitioner
also demanded compensation for families of individuals who may have died after
receiving the vaccine.
●
The controversy arose after
pharmaceutical company AstraZeneca admitted in U.K. court documents that its
vaccine could potentially cause Thrombosis with Thrombocytopenia Syndrome
(TTS).
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The petition emphasized the need
for an expert panel to assess the risks and hazardous consequences of
administering Covishield to citizens. It highlighted that more than 175 crore
doses of Covishield had been administered in India and raised concerns about an
increase in deaths due to heart attacks and sudden collapses, even among young
individuals.
58.4 Conclusion:
The journey of Covishield, from its development to the
controversies(related to rare side effects like low platelet counts and blood
clots) surrounding it, has been marked by both hope and skepticism. Despite
these challenges, real-world studies show that it remains safe and effective.
Globally, legal battles and health claims have arisen, but hope persists as we
continue our collective pursuit of public health.
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