Not only did the scientists find that they succeeded surprisingly well in the case of the new SARS-CoV-2 virus, but that special T cells could even surprisingly detect large parts of the new pathogen. In the first examination, Weiskopf and colleagues also confronted older blood samples from 2015 to 2018 with the new virus.
They noticed that T cells in almost half of the samples taken long before the Covid 19 pandemic showed a reaction to virus parts. Here one could be dealing with cross-immunity “that is caused by normal common cold viruses,” Weiskopf told APA at the time.
Different immune response
The scientist has now investigated this assumption with the first author of the new study, Jose Mateus: Again, they confronted blood samples taken before 2019 with over 100 parts of the new corona virus. It was shown that a whole range of T cells reacted both to SARS-CoV-2 and to a range of human coronaviruses that trigger normal colds. The strongest immune responses were triggered by the characteristic spike protein of the SARS-CoV-2 virus, which the pathogen uses to penetrate human cells.
Cell information from previous diseases
In contrast to the neutralizing antibodies produced by the B lymphocytes, which the immune system can only position very specifically against individual human cold viruses and not against the new coronavirus, the T cells can apparently also use their information acquired through previous diseases in combat against the new pathogen.
According to Weiskopf and colleagues, this could explain at least to some extent why Covid 19 disease takes such different courses.