The pharmacovigilance data confirmed the CVST incidences with all genetic vaccines (viral or non-viral vector), however, the regulatory authorities in their recent investigations reported that the CVST was unusually accompanied with thrombocytopenia in subjects injected with CoViD-19 viral vector vaccines (such as AstraZeneca and J&J/Janssen) than those injected with mRNA vaccines. We, therefore, looked at the preclinical studies of these vaccines to ascertain their biodistribution to body tissues (for instance brain) beyond the injection site for a possible explanation of the rare fatal clots formed in the brain. The biodistribution of ChaAdOx1 in mice confirmed the delivery of vaccine into the brain tissues. The vaccine may therefore spur the brain cells to produce CoViD spike proteins that may lead to an immune response against brain cells, or it may spark a spike protein-induced thrombosis. This may explain the peculiar incidences of the fatal CVST observed with viral vector-based CoViD-19 vaccines. It is anticipated that other vaccines using similar technology such as AstraZeneca/Oxford (Chimp adenoviral vector), J&J/Janssen (Human adenoviral vector 26), CanSinoBio (Human adenoviral vector 5), and Sputnik V (Human adenoviral vectors 26 and 5), may also lead to the same safety concerns.
|Publication status||E-pub ahead of print - 15 Apr 2021|