AstraZeneca acknowledges Covishield vaccination’s rare side effect. Concerned?

TTS is a rare side effect of AstraZeneca’s Covid vaccine. AstraZeneca has acknowledged in court documents for the first time that its vaccine can elevate the risk of a rare and serious blood clot.

The vaccine, developed in collaboration with Oxford University, is known as the Oxford-AstraZeneca Covid vaccine, sold as Covishield in India and Vaxzevria in Europe. It is a viral vector vaccine developed using the modified chimpanzee adenovirus ChAdOx1.

Covishield, manufactured and marketed in India in partnership with Serum Institute of India (SII), was widely administered in the country. The risk of TTS occurring as part of Vaccine-induced Immune Thrombotic Thrombocytopenic Purpura (VITTP) has been reported.

The incidence of TTS has been low, with about one in 50,000 cases, but in a large population, the number becomes significant. TTS is a rare condition resulting from an abnormal immune response and has been linked with adenovirus vector vaccines.

A report from the WHO in May 2021 has also addressed this association. AstraZeneca has admitted in UK court documents that its Covid vaccine can cause a rare blood clot risk.

About 51 cases have been filed in the UK High Court against the company over claims of death and serious injury caused by the vaccine. Although AstraZeneca is contesting the claims, it has acknowledged in a legal document submitted to the High Court that its vaccine can, in very rare cases, cause TTS.

In India, almost 90% of people who received the Covid vaccine received the AstraZeneca vaccine, known as Covishield. The vaccine is made from a harmless cold virus from chimpanzees, genetically modified to match the SARS-CoV-2, the virus responsible for Covid-19.

The mechanism of potential TTS risk involves the formation of blood clots due to a reaction with antibodies, which can lead to disastrous adverse effects. Despite the rare occurrence of TTS, people who are vaccinated have an overall lower risk of death from Covid and related complications.

The benefits of Covid vaccines far outweigh the risks, and vaccines have prevented hundreds of thousands of deaths. It is crucial to distinguish between complications caused by Covid itself, long-Covid, and the vaccine, which remains debatable and indistinguishable for the scientific and legal communities.