The following is a summary of “Antibody and T-Cell Subsets Analysis Unveils an Immune Profile Heterogeneity Mediating Long-term Responses in Individuals Vaccinated Against SARS-CoV-2,” published in the February 2023 issue of Infectious Diseases by Agallou, et al.

There was an urgent need to comprehend the underlying mechanisms of vaccine-induced interindividual immune response differences given that coronavirus disease 2019 (COVID-19) was still growing despite widespread vaccination.

In 127 people who received the BNT162b2 vaccine, the mRNA-1273 vaccine, or the ChAdOx1-nCoV-19 vaccine.

High spike- and RBD-specific antibody titers and neutralizing activity in comparison to ChAdOx1-nCoV-19 immunization demonstrated that both mRNA vaccines elicited faster and stronger humoral responses. Regardless of the vaccine given, a declining trend in humoral reactions was seen at 7 months after vaccination. A diverse immunological profile among BNT162b2-vaccinated people was shown by correlation analysis between anti-S1 IgG and interferon-γ (IFN-γ) production. With regard to the high-responder group, immunization led to significant populations of polyfunctional memory CD4+ helper T cells (TH1), follicular helper T cells (TFH), and T cells with signs of stemness (TSCM), as well as high neutralizing antibody production that lasted for up to 7 months. Low responders, on the other hand, had significantly fewer memory T cells, antibody titers, and production capacities of interleukin-2 and IFN-γ.

They found that the capacity of an individual to generate antigen-specific persistent memory T-cell populations correlated with long-term humoral responses.