The Oxford-AstraZeneca vaccine, known in India as Covishield, may be associated with a very small risk of developing a blood condition characterized by low platelet counties, according to a national study in the United Kingdom. The greatest risk of the condition, known as idiopathic thrombocytopenic purple (ITP), is estimated at 11 per million doses, similar to the figures observed in vaccines for influenza, and measles, mumps and rubella (MMR), said The researchers.
A low platelet number: Blood cells that help prevent blood loss when ships are damaged, may result in any symptoms or can cause a higher risk of bleeding or, in some cases, they coagulate, they said.
The team, led by researchers from the University of Edinburgh in the United Kingdom, pointed out that people in most of ITP risk tended to be older, a median age of 69, and had at least one underlying chronic health problem , as a coronary. Cardiac disease, diabetes or chronic kidney disease.
The researchers could not establish a definitive link between other forms of coagulation, including the rare form called brain venous sinus thrombosis or CVST, due to the minimum number of cases in people vaccinated in the study.
The study of 5.4 million people in Scotland, of which 2.5 million had received their first dose of vaccines, is the first analysis of ITP events, coagulation and bleeding after vaccination for a complete country.
The authors of the study, published in the journal Nature Medicine on Wednesday, emphasized that the increase in the possibilities of developing ITP after receiving the vaccine remains less than the risk of developing it due to Covid-19.
They noted that the rare risk should not dissuade the deployment of the vaccine program.
The same risk of ITP was not found for the Pfizer-Biontech vaccine. Other vaccines were not included in the study.
The researchers analyzed a data set as part of the EVA II project, which uses data from anonymous linked patients to track the pandemic and vaccine is deployed in real time.