German scientists find cause and solution to AstraZeneca and Janssen thrombi
Categories:
Posted on May 28, 2021
As of today, the United Kingdom has registered 309 cases of thrombi among the 33 million people who have received the AstraZeneca vaccine. In Europe, the figure is 142 among the 16 million who have received the drug from Oxford and Janssen.
A group of German scientists claims to have discovered the cause of thrombi caused by these vaccines. Best of all, the researchers believe that the sera can be modified to avoid these adverse reactions, according to the Financial Times.
Rolf Marschalek, a professor at Goethe University (Frankfurt) who has studied the side effects of these drugs in depth, explained to the British newspaper that the problem lies in the adenovirus vectors that both vaccines use to introduce the protein of the spicule of Sars-CoV-2.
In a preprint of the study published this Wednesday, the researchers point out that the mechanism used by vaccines implies that the spicule —fundamental in the infection— reaches the nucleus of the cell, instead of the cytosol. Once inside the nucleus, some parts of the protein splice or break off and create new versions, which cannot bind to the cell membrane. Those parts of the protein that remain floating are expelled from the cell and causing these "very rare" thrombi.
In contrast, messenger RNA-based vaccines, such as those from BioNTech/Pfizer and Moderna, carry genetic material from the spike into the cell's fluid and never enter the nucleus.
Thrombi can be avoided
Vaccines can be modified to avoid thrombi. "With the data we have in our hands", says Marschalek, "we can tell drug companies how to mutate these sequences, encoding the spike protein in a way that avoids unwanted splicing reactions."
In fact, Johnson and Johnson would already be "trying to optimise their vaccine", according to the British professor.
