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Covid-19: FDA authorizes Moderna vaccine as US starts vaccinating health workers

BMJ 2020; 371 doi: (Published 21 December 2020) Cite this as: BMJ 2020;371:m4924

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Rapid Response:

Is it possible to conduct a double-blind placebo vaccine study in humans?

Dear Editor

I have read the response by Jean-Luc Mommaerts and Anne-Mieke Vandamme [1] with interest and also the article in BMJ Opinion by Peter Doshi [2], and I pose the very simple question whether the double blind placebo vaccine trial is ever a realistic enterprise. For instance, I read in the Pfizer-BioNTech submission to the FDA for their Covid vaccine [3] (p.6):

"The most common solicited adverse reactions were injection site reactions (84.1%), fatigue (62.9%),
headache (55.1%), muscle pain (38.3%), chills (31.9%), joint pain (23.6%), fever (14.2%); severe adverse
reactions occurred in 0.0% to 4.6% of participants, were more frequent after Dose 2 than after Dose 1,
and were generally less frequent in participants ≥55 years of age (≤2.8%) as compared to younger
participants (≤4.6%)."

It seems therefore that in most cases the subject will have some considerable inkling whether they have received the active vaccine or the inert placebo. The study is billed as double blind placebo but is the claim credible?

[1] Jean-Luc Mommaerts and Anne-Mieke Vandamme, ‘ Blindness breach powered by inadvertent placebo proneness may confound COVID-19 vaccination study results’, 23 December 2020,



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

28 December 2020
John Stone
UK Editor
London N22