AstraZeneca Covid-19 Vaccine Linked to Fatal Blood Clotting Disorder

AstraZeneca's Covid-19 vaccine is associated with another rare but fatal blood clotting disorder, according to new findings published in the New England Journal of Medicine. These results have significant implications for enhancing vaccine safety (1^✔ ✔Trusted Source
AstraZeneca vaccine: Blood clots are “extremely rare” and benefits outweigh risks, regulators conclude

Go to source). The British-Swedish pharmaceutical company AstraZeneca, in collaboration with Oxford University, acknowledged that their Covid vaccine can, in extremely rare cases, cause Thrombotic Thrombocytopenic Syndrome (TTS). Researchers recently found that the vaccine increases the risk of vaccine-induced immune thrombocytopenia and thrombosis (VITT), a rare and fatal clotting disorder.

Rare Symptoms After Administration of Covid vaccine

Although VITT was not previously known, it emerged during the Covid-19 pandemic in 2021 following the use of the adenovirus vector-based Oxford-AstraZeneca vaccine, marketed as Covishield in India and Vaxzevria in Europe. The disorder is caused by an unusually harmful blood autoantibody targeting a protein called platelet factor 4 (PF4).

In 2023, researchers from Canada, North America, Germany, and Italy reported a similar disorder with the same PF4 antibody that was fatal in some instances after natural adenovirus infections (common cold). Recent research by Flinders University in Australia and international experts revealed that the PF4 antibodies in both adenovirus infection-associated VITT and the classic adenoviral vector VITT share identical molecular signatures.

Professor Tom Gordon from Flinders University noted that the pathways for producing lethal antibodies in these disorders are virtually identical and likely share genetic risk factors. He emphasized that the findings have crucial clinical implications, suggesting that insights from VITT could apply to rare cases of blood clotting following adenovirus infections and inform future vaccine development.

In 2022, the same research team decoded the molecular structure of the PF4 antibody and identified a genetic risk factor. Their recent findings further underscore the importance of improving vaccine safety.

AstraZeneca had previously admitted in a legal document to the High Court in February that their Covid vaccine could, in very rare instances, cause TTS. This rare side effect, linked to at least 81 deaths in the UK and numerous serious injuries, prompted the company to withdraw the vaccine's marketing authorization from Europe and other global markets.

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Reference:

1. AstraZeneca vaccine: Blood clots are "extremely rare" and benefits outweigh risks, regulators conclude - (https://pubmed.ncbi.nlm.nih.gov/33832929/)

Source-Medindia