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Cross reactive immunity to COVID?
Several studies now suggest that T cells reactive to COVID may be present even in persons without prior exposure to SARS CoV-2 suggesting presence of cross reactive immunity presumably from prior corona virus infections.
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Several studies now suggest that T cells reactive to COVID may be present even in persons without prior exposure to SARS CoV-2 suggesting presence of cross reactive immunity presumably from prior corona virus infections.
Thread with links
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La Jolla: 40-60% samples from persons with no prior exposure to COVID had T cell responses. @CellPressNews
https://www.cell.com/cell/fulltext/S0092-8674(20)30610-3
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https://www.cell.com/cell/fulltext/S0092-8674(20)30610-3
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Netherlands: 2 of 10 healthy controls with no prior exposure to COVID had evidence of reactive T cells.
https://immunology.sciencemag.org/content/5/48/eabd2071.full
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https://immunology.sciencemag.org/content/5/48/eabd2071.full
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Karolinska: Twice as many close family contacts of COVID patients had memory T cells against SARS CoV-2 compared to antibodies. https://www.biorxiv.org/content/10.1101/2020.06.29.174888v1.full.pdf
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Germany: Cross-reactive SARS-CoV-2 T-cell epitopes revealed preexisting T-cell responses seem in 81% of unexposed individuals, and validation of similarity to common cold human coronaviruses.
https://www.researchsquare.com/article/rs-35331/v1
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https://www.researchsquare.com/article/rs-35331/v1
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Singapore: Samples from patients with the original 2003
SARS had T cells reactive to SARS CoV-2.
https://www.biorxiv.org/content/10.1101/2020.05.26.115832v1.full.pdf
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SARS had T cells reactive to SARS CoV-2.
https://www.biorxiv.org/content/10.1101/2020.05.26.115832v1.full.pdf
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These studies raise the question whether seroprevalence studies underestimate the proportion of the population that has some degree of immunity against COVID
We dont know if these T cell responses are protective and for how long. We still need to continue all the precautions
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We dont know if these T cell responses are protective and for how long. We still need to continue all the precautions
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But they may partially explain the rapid decrease in cases in many hotspots despite low levels of seroprevalence.
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Is cross reactive immunity the reason why in the Antarctica cruise ship report, we had 10 rooms with 2 passengers each, in which one had COVID and one didn’t despite 20-30 days of close contact? https://thorax.bmj.com/content/early/2020/06/09/thoraxjnl-2020-215091
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