Well, there are T cells from prior infections with human coronaviruses that cause the common cold:
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T Cells From Common Colds Cross-Protect Against Infection With SARS-CoV-2
People with higher levels of T cells from common cold coronaviruses are less likely to become infected with SARS-CoV-2.
A new study, published in Nature Communications and led by Imperial College London researchers, provides the first evidence of a protective role for these T cells. While previous studies have shown that T cells induced by other coronaviruses can recognise SARS-CoV-2, the new study examines for the first time how the presence of these T cells at the time of SARS-CoV-2 exposure influences whether someone becomes infected. . . .
Dr Rhia Kundu, first author of the study, from Imperial’s National Heart & Lung Institute, says: “Being exposed to the SARS-CoV-2 virus doesn’t always result in infection, and we’ve been keen to understand why.
We found that high levels of pre-existing T cells, created by the body when infected with other human coronaviruses like the common cold, can protect against COVID-19 infection.<<<
A new study provides the first evidence of a protective role for common cold T cells in combating SARS-CoV-2.
www.technologynetworks.com
While cross-reactive immunity between human coronavirus and SARS-CoV-2 may contribute to host protection, validating evidences are still scarce. Here the authors assess a cohort of 52 donors with immediate-early contact with SARS-CoV-2 to correlate higher frequency of cross-reactive T cells with...
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