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Feature Coronavirus

Covid-19: Do many people have pre-existing immunity?

BMJ 2020; 370 doi: (Published 17 September 2020) Cite this as: BMJ 2020;370:m3563

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"Fine-aerosol viral RNA was also positively associated with having influenza vaccination"

Dear Editor

comment from Cunningham reminded me also of these findings:

"The association of current and prior year vaccination with increased shedding of influenza A might lead one to speculate that certain types of prior immunity promote lung inflammation,
airway closure, and aerosol generation. This first observation of the phenomenon needs confirmation. If confirmed, this observation, together with recent literature suggesting reduced protection with annual vaccination, would have implications for influenza vaccination recommendations and policies." (title is also taken from summary of the study)

Seems that with the (human) immune system - hence with vaccination - we're playing a game whose rules are not well understood yet, hence for some class of pathogens the odds of doing more harm than good, via 'panic-mode' mass vaccination, seem still not negligible.

Competing interests: No competing interests

20 September 2020
Mark Dublin
sw engineer