The COVID-19 pandemic allowed us to study primary immune responses to SARS-CoV-2 infection or vaccination. Some healthy individuals may have pre-existing immunity: induction of T cells from the memory repertoire that were originally primed by another pathogen. We found that this pathogen is, in some cases, the cytomegalovirus, which is surprising considering the sequence dissimilarity with SARS-CoV-2. However, the avidity of the cross-reactive T cells for SARS-CoV-2 is likely insufficient to change the course of the disease.
Primary T cell responses are effectively induced in most healthy individuals after infection or vaccination, thereby reducing the risk of severe disease. However, the ability of patients with hematological disorders to develop strong T cell responses is unclear, since they are often immunocompromised due to the disease or therapy that they receive. Fortunately, we found that the SARS-CoV-2 mRNA vaccines were able to efficiently induce T cell...
Show moreThe COVID-19 pandemic allowed us to study primary immune responses to SARS-CoV-2 infection or vaccination. Some healthy individuals may have pre-existing immunity: induction of T cells from the memory repertoire that were originally primed by another pathogen. We found that this pathogen is, in some cases, the cytomegalovirus, which is surprising considering the sequence dissimilarity with SARS-CoV-2. However, the avidity of the cross-reactive T cells for SARS-CoV-2 is likely insufficient to change the course of the disease.
Primary T cell responses are effectively induced in most healthy individuals after infection or vaccination, thereby reducing the risk of severe disease. However, the ability of patients with hematological disorders to develop strong T cell responses is unclear, since they are often immunocompromised due to the disease or therapy that they receive. Fortunately, we found that the SARS-CoV-2 mRNA vaccines were able to efficiently induce T cell responses in most patients with aplastic anemia or hematological malignancies. A combined vaccine-induced T-cell and antibody deficiency was rare among these patient groups. Furthermore, antibody titers or the absolute counts of T cells do not accurately predict the ability to develop vaccine-induced T-cell responses. This highlights the beneficial value of mRNA vaccination in these patient groups.
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