AstraZeneca Acknowledges Covishield Vaccine’s Uncommon Side-Effect. Should You Be Concerned?

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.

Infectious disease expert Dr. Ishwar Gilada, told IANS, “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.”

Dr Rajeev Jayadevan, co-chairman of the Indian Medical Association’s National Covid-19 Task Force, told news agency 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.”

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. 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.

AstraZeneca is contesting the claims but has accepted, in a legal document submitted to the High Court in February, that its Covid vaccine ‘can, in very rare cases, cause TTS.’ AstraZeneca’s Covid vaccine, known as Covishield in India, is made from a harmless cold virus, which is from chimpanzees and is called adenovirus.

Dr. Ishwar stated, “Once this virus is genetically modified or engineered to match the SARS-CoV-2, a causative organism for Covid-19, this works on a spike protein. So, the vaccine is incorporated with the S spike protein genetic sequence.”

Explaining the mechanism of potential TTS risk, the doctor said that the vaccine is injected in the arm which is in the deltoid muscle. “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.

Such clots in the brain and heart can cause disastrous adverse effects,” the doctor said. Concerning the vaccine’s recipients, Dr. Ishwar stated, “No, we need not because it has happened to a very few people,” and added, “The difficulty is to distinguish between the complications that are caused by Covid itself or long-Covid or the vaccine.

That remains debatable and indistinguishable for the scientific community as also the legal fraternity.” Dr. Rajeev emphasized, “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.”

He also mentioned the benefits of vaccination in preventing Covid-related deaths. *(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.

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