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Covid-19: European countries suspend use of Oxford-AstraZeneca vaccine after reports of blood clots

BMJ 2021; 372 doi: (Published 11 March 2021) Cite this as: BMJ 2021;372:n699

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Yellow Card reports compared for Oxford/AstraZeneca and PfizerBioNTech products

Dear Editor,

I note the very different profiles the of the Oxford Astra/Zeneca and PfizerBioNTech products according Yellow Card data published by the MHRA complete to 28 February. Although more Pfizer doses had been delivered (10.7m vs. 9.7m) [1] the Oxford vaccine had generated many more Yellow Card reports (54,180 Yellow card reports vs. 33,207), generated many more adverse reactions (201,622 vs 94,809) and more fatal reactions (275 vs 227) [2,3]. This means that there are an average of 3.7 reactions listed on each card for the Oxford vaccine vs. 2.9 for the Pfizer, but the mode of reporting in which individual case histories are invisible militates against certain kinds of analysis, as it did with Pandemrix vaccine in the Swine Flu “pandemic” of 2009 when the MHRA failed to detect narcolepsy as an adverse effect of the product [4]. I calculate that there has been about one Yellow Card report in 179 doses for the Oxford vs. one in 322 for the Pfizer, but obviously this is a passive system. It might also be pointed out that the sharply contrasted profiles of two Covid products makes it statistically implausible that we are dealing with random noise, and it is now a very large body of data.




[4] John Stone, ‘Is the MHRA up to it?’, 19 January 2021,

Competing interests:, an on-line daily journal, concerns itself with the potential environmental sources for the proliferation of autism, neurological impairment, immune dysfunction and chronic disease. I receive no payment as UK Editor. I also moderate comments for the on-line journal ‘The Defender’ for which I am paid. I am also a member of the UK Medical Freedom Alliance

16 March 2021
John Stone
UK Editor
London N22