NEW DELHI: UK-based drug major
AstraZeneca
‘s decision to
withdraw
its Covid-19
vaccine
globally, days after admitting to side effects, prompted Serum Institute of India to disclose that it had stopped manufacturing
Covishield
in Dec 2021 due to a fall in demand as well as the emergence of new variants.
“With India achieving high vaccination rates in 2021 and 2022, coupled with the emergence of new mutant variant strains, the demand for previous vaccines diminished significantly.
Consequently, since Dec 2021, we have stopped the manufacture and supply of additional doses of Covishield,” said a
SII
spokesperson.
The global drug giant had recently admitted to Vaxzervria causing Thrombosis with Thrombocytopenia (TTS) in very rare cases.
Covishield accounted for nearly 80% of Covid-19 vaccine doses administered in India. AstraZeneca said its decision to withdraw marketing authorisation of Vaxzevria was due to a “surplus of available updated vaccines” since the pandemic.
The SII spokesperson said the company fully understood the ongoing concerns. ” We have disclosed all rare to very rare side effects, including Thrombosis with TTS, in the packaging insert in 2021,” the spokesperson said.
TTS refers to the formation of blood clots with low platelet counts. The condition is rare but is usually serious, particularly when the blood clot happens in major vessels, say doctors.
The epidemiologic data on TTS among Indians is not known but in the UK, researchers have found 2.4 cases of TTS per lakh vaccines. “As the number of cases are small, studies face challenges in establishing risk factors. However, the UK study found that male gender and age above 65 years put people at higher risk of TTS . Moreover, chronic diseases of heart, kidney, liver, neurological diseases and cancer were found to place such affected persons at higher risk of developing TTS,” Dr Kameshwar Prasad, former head of neurology at AIIMS told TOI.
