SARS-CoV2 mRNA Vaccine-Specific B-, T- and Humoral Responses in Adolescents After Kidney Transplantation

Protection of adult kidney transplant recipients against SARS-CoV2 was shown to be strongly impaired owing to low reactogenicity of available vaccines. So far, data on vaccination outcomes in adolescents are scarce due to later vaccination approval for this age group. We therefore comprehensively analyzed vaccination-specific humoral-, T- and B-cell responses in kidney transplanted adolescents aged 12-18 years in comparison to healthy controls 6 weeks after standard two-dose BNT162b2 (Comirnaty; Pfizer/BioNTech) vaccination. Importantly, 90% (18/20) of transplanted adolescents showed IgG seroconversion with 75% (15/20) developing neutralizing titers. Still, both features were significantly diminished in magnitude compared to controls. Correspondingly, spike-specific B cells were quantitatively reduced and enriched for non-isotype-class-switched IgD(+)27(+) memory cells in patients. Whereas spike specific CD4(+) T cell frequencies were similar in both groups, cytokine production and memory differentiation were significantly impaired in transplant recipients. Although our data identify limitations in all arms of vaccine-specific immunity, the majority of our adolescent patients showed robust humoral responses despite antimetabolite-based treatment being associated with poor vaccination outcomes in adults.

Automated summary

Protection against SARS-CoV2 is impaired in kidney transplant recipients due to low vaccine reactogenicity. After two doses of BNT162b2 vaccine, 90% of transplanted adolescents showed IgG seroconversion, but the response was significantly reduced compared to healthy controls. Spike-specific B cells were decreased and enriched for non-isotype-class-switched memory cells in patients. Although limitations in vaccine-specific immunity were identified, most adolescent patients showed robust humoral responses.