Trial Site News published just today the evidence that we have been waiting for…an investigation about the human immune system’s “normal” response to SARS-CoV-2 in terms of “what amount of weaponry” is left available, after 1) infection, 2) immune system defense and 3) recovery…without a vaccination and compared and contrasted these findings with the vaccine-triggered human immune system’s specific antibody response to SARS-CoV-2, including the measurement of lasting defenses.
“Both SARS-CoV-2 infection and vaccination were found to elicit SARS-CoV-2-specific antibody responses.”
“COVID-19 patients had a striking expansion of antibody-producing
plasmablasts, with evidence of clonal cells in this cluster. However, we
did not detect appreciable expansion of plasmablasts in circulation of
individuals immunized with SARS-CoV-2 BNT162b2 mRNA vaccine, despite a
robust antibody response.”
“Recent studies emphasize generation of antigen-specific T cells in
protective immunity against SARS-CoV-2 infection and it is becoming
increasingly clear that successful vaccines need to engage the cellular
adaptive immune response<sup>100–102</sup>. Indeed, humoral immune responses may be less effective against new SARS-CoV-2 variants<sup>88,103</sup>.
Conversely, SARS-CoV-2-specific CD8 T cell responses, which target a
broad range of epitopes, remain largely intact against new variants
presently in circulation<sup>104</sup>.
Our analysis revealed that both SARS-CoV-2 infection and, to a lesser
degree, vaccination elicit clonal CD8 effector T cell responses.”
“We also observed a strong clonal response in CD8/CD26 T<sub>EM</sub> cells in all volunteers following immunization – a feature of adaptive response that was notably absent in COVID-19 patients.”
“Peripheral immune cells of COVID-19 patients were enriched in T cells,
NK cells, and γδ T cells with a highly activated phenotype and elevated
expression of genes associated with cytotoxic effector functions (GZMA, GZMB, GZMH, PRF1, GNLY, NKG7, and IL-32).
We observed the presence of cytotoxic CD4 T cells in COVID-19 patients
that were largely absent in healthy volunteers following immunization.”
As reported in the authors’ manuscript, the authors point out that beyond antibody production, the knowledge behind COVID-19 vaccine immune response “remains largely uncharacterized.” Thus the authors sought out to provide more clarity to this important topic.
As described in their abstract, the study team conducted a study in a lab based on “multimodal single-cell sequencing on peripheral blood of patients with acute COVID-19” as well as a cohort of healthy volunteers before and after they received the mRNA vaccine known as BNT162bs developed by Pfizer-BioNTech.
Their mission: compare the immune response elicited by the natural pathogen and in parallel compare to the response triggered by the vaccine product in emergency use authorization (EUA). Then the investigational team employed phenotypic and transcriptional profiling of each of the patient samples’ immune cells along with “reconstruction of the B and T cell antigen receptor rearrangement of individual lymphocytes,” affording the team the opportunity to characterize and compare the host responses to both A) the virus and B) defined viral antigens.
Both the natural infection and mRNA vaccination-induced robust innate and adaptive responses but the authors noticed material differences in the two cohorts. TrialSite provides a brief table:
The authors concluded that “far-reaching implications for immunity to SARS-CoV-2″ are implicated from their research […]
This study about the response of the human immune system to SARS-CoV-2 shows that the other parts of the body’s immune system (besides specific antibodies triggered by a vaccine’s active nanolipid-encased mRNA “switches”) are to be considered in determination of post-COVID-19 long-term immunity.