AstraZeneca acknowledges rare side-effect of Covishield vaccine. Cause for concern?

TTS – a blood clot disorder — is a rare side effect of AstraZeneca’s Covid vaccine. This comes after reports said that AstraZeneca has for the first time accepted in court documents that its vaccine, developed in partnership with Oxford University, can raise the risk of a rare and serious blood clot. The Oxford-AstraZeneca Covid vaccine, sold as Covishield in India and Vaxzevria in Europe 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 — to almost 90 per cent of the Indian population. “Thrombotic Thrombocytopenic Syndrome (TTS) is one of the rare but very serious adverse effects that has happened as part of Vaccine-induced Immune Thrombotic Thrombocytopenic Purpura (VITTP). The incidence has been as low as one in 50,000 (0.002 per cent), but in a huge population, the number becomes sizeable,” infectious disease expert Dr. Ishwar Gilada, told IANS.

“TTS is a very rare condition resulting from an abnormal immune response. Although it has several causes, it has also been linked with adenovirus vector vaccines and the WHO published a report on May 27, 2021 about it,” Dr Rajeev Jayadevan, co-chairman of the Indian Medical Association’s National Covid-19 Task Force, told news agency IANS. What is the case?

The British-Swedish multinational pharmaceutical company has admitted for the first time in the UK court documents that its Covid vaccine can cause a rare blood clot risk, the Telegraph reported. About 51 cases have been lodged in the UK High Court against the pharmaceutical giant over claims that its Covid vaccine caused death and serious injury. The victims and grieving relatives have sought damages, estimated to be worth up to 100 million pounds, the report said.

AstraZeneca’s Covid vaccine and link to TTS? In India, almost 90 per cent of people who received Covid vaccine, received the AstraZeneca vaccine which in India is called Covishield. It is made from a harmless cold virus, which is from chimpanzees and it is called adenovirus.

Explaining the mechanism of potential TTS risk, it is theorised that such antibodies then react and clump together with PF4, forming the blood clots that have become so heavily linked with the vaccine. Should all Covishield vaccine takers be worried? “No, we need not because it has happened to a very few people,” Dr. Ishwar said.

Importantly, Dr. Rajeev said, “People who are vaccinated have an overall lower risk of death from Covid as well as complications such as post-Covid heart attacks and strokes afterward”.