A coronavirus infection presents a way higher risk of developing a grume than the primary dose of either the Oxford/AstraZeneca or the Pfizer/BioNTech jab, an outsized study led by the University of Oxford said on Friday.
The research used findings from quite 29 million people that were vaccinated with the primary doses of either vaccine between December 2020 and April 2021 The findings showed although there was an increased risk of getting a grume after having the primary doses of either vaccine, it had been much greater in someone who had tested positive for COVID-19 caused by the SARS-CoV-2 virus.
“People should remember of those increased risks after COVID-19 vaccination and seek medical attention promptly if they develop symptoms, but even be aware that the risks are considerably higher and over longer periods of your time if they become infected with SARS-CoV-2,” said Julia Hippisley-Cox, Professor of Clinical Epidemiology and General Practice at the University of Oxford and lead author of the paper The study covered thrombocytopenia – a condition with low platelet counts – and thromboembolic events (blood clots) following vaccination for COVID-19, a number of an equivalent events which had led to restricted use during a number of nations of the Oxford/AstraZeneca vaccine – being produced and administered in India as Covishield.
Writing within the ‘British Medical Journal’ (BMJ), the researchers detail the findings from over 29 million people vaccinated with first doses of either the ChAdOx1 nCov-19 or Oxford/AstraZeneca vaccine or the BNT162b2 mRNA or Pfizer/BioNTech vaccine They conclude that with both of those vaccines, for brief time intervals following the primary dose, there are increased risks of some haematological and vascular adverse events resulting in hospitalisation or death.
The authors further note that the danger of those adverse events is substantially higher and for a extended period of your time , following infection from the SARS-CoV-2 coronavirus than after either vaccine This research is vital as many other studies, while useful, are limited by small numbers and potential biases. Electronic healthcare records, which contain the detailed recording of vaccinations, infections, outcomes and confounders, have provided us with an upscale source of knowledge with which to perform a strong evaluation of those vaccines, and compare to risks related to COVID-19 infection,” explains Prof Hippisley-Cox.
All of the coronavirus vaccines currently in use are tested in randomised clinical trials, which are unlikely to be large enough to detect very rare adverse events When rare events are uncovered, then regulators perform a risk-benefit analysis of the medicine; to match the risks of the adverse events if vaccinated versus the advantages of avoidance of the disease – during this case, COVID-19.
Aziz Sheikh, Professor of medical care Research & Development and Director of the Usher Institute at the University of Edinburgh and a co-author of the paper, said: “This enormous study, using data on over 29 million vaccinated people, has shown that there’s a really small risk of clotting and other blood disorders following the primary dose COVID-19 vaccination.
“Though serious, the danger of those same outcomes is far higher following SARS-CoV-2 infection On balance, this analysis therefore clearly underscores the importance of getting vaccinated to scale back the danger of those clotting and bleeding outcomes in individuals, and since of the substantial public health benefit that COVID-19 vaccinations offer,” Sheikh said.
In the paper, the team of authors from the University of Oxford, University of Leicester, Guys and St Thomas’ NHS Foundation Trust, the medical care National Audit & Research Centre, the London School of Hygiene and medicine , the University of Cambridge, the University of Edinburgh and therefore the University of Nottingham, compared rates of adverse events after vaccination with Pfizer/BioNTech and Oxford/AstraZeneca vaccines with rates of an equivalent events after a positive SARS-CoV-2 test result.
For this, they used routinely collected electronic health records to guage the short-term risks (within 28 days) of hospital admission with thrombocytopenia, venous thromboembolism (VTE) and arterial thromboembolism (ATE), using data collected from across England between December 1, 2020 and April 24, 2021 Other outcomes studied were cerebral sinus thrombosis (CVST), ischaemic stroke , myocardial infarct and other rare arterial thrombotic events.