Thread by @SorenSchifter

1/n. The SARS-CoV-2 genome is 87% identical to SARS-CoV and higher than 75% with the other 5 human coronaviruses, see Table C. - It is no wonder that there is background immunity and that many are not susceptible.
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2/n. The fact that not all are susceptible was public knowledge from the start of the epidemic from observations on Diamond Princess.

https://twitter.com/SorenSchifter/status/1314077654446944257?s=20

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3/n. The aircraft carrier Theodore Roosevelt also had less than 20% with a positive test, and only about 50% of individuals with a positive test had symptoms.

https://twitter.com/SorenSchifter/status/1256216403222413313?s=20

#Covid_19 #COVID19 #coronavirus #Corona

4/n. More documentation for preexisting T cell immunity to SARS- CoV-2.
ncbi.nlm.nih.gov/pmc/articles/P…
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5/n. There is also preexisting humoral immunity to SARS-CoV-2.
ncbi.nlm.nih.gov/pmc/articles/P…
#Covid_19 #COVID19 #coronavirus #Corona