> Importantly, we detected SARS-CoV-2−reactive CD4+ T cells in ~40-60% of unexposed individuals, suggesting cross-reactive T cell recognition between circulating ‘common cold’ coronaviruses and SARS-Cov-2
This is saying that 40-60% of existing immune responses (learned over many years of previous coronaviruses) are also protective against the SARS-Cov-2 virus which causes Covid-19 disease.
There is a time-based arms race between virus replication & immune defense. If these subjects are otherwise healthy, their immune system should have a good chance of clearing the Covid-19 virus successfully, because it has a "running start" against the new virus.
After recovery, their adaptive immune system should have developed an additional immune response that is customized to defend against Covid-19.
This is saying that 40-60% of existing immune responses (learned over many years of previous coronaviruses) are also protective against the SARS-Cov-2 virus which causes Covid-19 disease.
There is a time-based arms race between virus replication & immune defense. If these subjects are otherwise healthy, their immune system should have a good chance of clearing the Covid-19 virus successfully, because it has a "running start" against the new virus.
After recovery, their adaptive immune system should have developed an additional immune response that is customized to defend against Covid-19.