[Morningstar] BERLIN -- Scientists in Europe said they had identified a mechanism that could lead the AstraZeneca PLC vaccine to cause potentially deadly blood clots in rare instances as well as a possible treatment for it.
Two teams of medical researchers in Norway and Germany have independently found that the vaccine could trigger an autoimmune reaction causing blood to clot in the brain, which would offer an explanation for isolated incidents across Europe in recent weeks.
Several European countries briefly halted their rollouts of the vaccine this week after more than 30 recipients were diagnosed with the condition known as cerebral venous sinus thrombosis, or CVST. Most of the people affected were women under the age of 55.
Continued from Page 3
The issue affected a tiny portion of those who had received the shot, however, and after investigating, the European drugs regulator ruled that the benefits outweighed the potential risks of the vaccine, and recommended vaccinations resume.
Pål André Holme, a professor of hematology and chief physician of the Oslo University Hospital who headed an investigation into the Norwegian cases, said his team had identified an antibody created by the vaccine that was triggering the adverse reaction.
"Nothing but the vaccine can explain why these individuals had this immune response," Prof. Holme said.
Norway's health authority cited the findings when announcing that it wouldn't resume the vaccination.
A team of German researchers around Andreas Greinacher, professor of transfusion medicine at the Greifswald University Clinic, said Friday they had independently come to the same conclusion as Prof. Holme.
In Germany, 13 cases of CVST were detected among around 1.6 million people who received the AstraZeneca vaccine. Twelve patients were women and three died.
The German researchers, who coordinated with colleagues in Austria, Ireland and Britain, said in a statement that patients who show symptoms four days after vaccination, such as headaches, dizziness or impaired vision, could be quickly diagnosed with a blood test. Prof. Greinacher said the news meant that people shouldn't fear the vaccine.
"Very, very few people will develop this complication," Prof. Greinacher said in a press conference Friday. "But if it happens, we now know how to treat the patients."
He said that, after a swift diagnosis, the condition could be treated in any midsize hospital. 
|
