Over a week after AstraZeneca announced a global withdrawal of its vaccine against coronavirus citing a slowdown in sales and availability of enough options in the market, new research has linked it to a rare disorder.

Researchers found that the AstraZeneca vaccine, sold in India under the brand name Covishield, is linked to a rare blood clotting disorder called Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT). 

While not new, VITT emerged as a new disease following adenovirus vector-based Oxford-AstraZeneca vaccine -- sold as Covishield in India and Vaxzevria in Europe -- at the height of the Covid pandemic in 2021.

"An unusually dangerous blood autoantibody directed against a protein termed platelet factor 4 (or PF4)" was found as the reason for VITT.

In separate research in 2023, scientists from Canada, North America, Germany and Italy described a virtually identical disorder with the same PF4 antibody that was fatal in some cases after natural adenovirus (common cold) infection.

Now in a new research, Flinders University in Australia and other international experts found that the PF4 antibodies in both adenovirus infection-associated VITT and classic adenoviral vector VITT share identical molecular fingerprints or signatures.

The researcher noted that the "findings have the important clinical implication that lessons learned from VITT are applicable to rare cases of blood clotting after adenovirus (a common cold) infections, as well as having implications for vaccine development".