A study of side effects after vaccination with AstraZeneca (AZN.L) anti-COVID-19 shots in Scotland found only an association with a virtually harmless bleeding condition and no association with brain clots, underscoring the rarity of potential complications.
A group of researchers led by the University of Edinburgh Professor Aziz Sheikh, who tracks the health of 5.4 million people in Scotland, found that around a further case of idiopathic thrombocytopenic purpura (ITP) per 100,000 people emerged after the first injection of the Astra vaccine.
ITP is a treatment-related condition with low platelet counts with a range of possible symptoms and has not caused any deaths among the cohort monitored for the study, which included 1.7 million recipients of the Astra vaccine, the authors said.
The study, published in the journal Nature Medicine on Wednesday, suggested a vague link to arterial coagulation or bleeding. But potentially fatal venous coagulation in the brain, known as CVST, which has caused concern in Europe, particularly Scandinavia, was not linked to the Astra shot in the data analysis.
Due to the rarity of CVST, the Scottish data sample may have been too small to allow for any conclusions, Aziz told a media briefing.
“The overall message is only the rarity of these results,” Aziz said.
“This is reassuring data and we would very much urge people to move on when they receive the invitation to be vaccinated,” he added.
Cases of low platelet counts in combination with blood clots reported in humans within a few weeks of receiving the Astra shot have resulted in limits imposed on the shot’s use on younger people across Europe, including some direct stops for all ages.
The UK Medical and Health Regulatory Agency (MHRA) had previously reported low platelet counts in combination with blood clots after vaccination with the AstraZeneca vaccine known as Vaxzevria was estimated to occur at a rate of approx. 1.3 in 100,000 first doses.
The European Union’s Drug Regulator has found a possible link between low platelet counts in combination with blood clots and the Vaxzevria vaccine and with Johnson & Johnson’s (JNJ.N) single dose shots. Read more
The EU body as well as the MHRA have maintained that the overall benefits of both vaccines outweigh any risks they pose.
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