Prevalence of COVID-19 in Kidney Transplant Patients in Relation to Their Immune Status after Repeated Anti-SARS-CoV-2 Vaccination

The prospective study was conducted to evaluate the prevalence of COVID-19 in kidney transplant patients in relation to their immune status after three doses of the BNT162b2 (Pfizer-BioNTech) vaccine during one post-pandemic year based on the experience of one center—Hospital of Lithuanian University of Health Sciences. Thirty-three patients were invited for a follow-up visit 3 to 6 weeks after anti-SARS-CoV-2 vaccination and were obliged to report having COVID-19 during the one-year post-pandemic period. Forty-two percent of patients developed antibody response against SARS-CoV-2 after the third dose of the vaccine. The number of COVID-19 cases during the post-pandemic period did not differ significantly between seropositive and seronegative patients. However, only seronegative patients were hospitalized due to COVID-19. The anti-SARS-CoV-2 antibody titer in seropositive patients correlated with a relative number of CD3(+) cells (R = 0.685, p = 0.029). The CD8(+)/CD38(+) ratio in this group increased 2-fold after the anti-SARS-CoV-2 vaccination. Higher antibody response to the COVID-19 vaccine was associated with better kidney function. The anti-SARS-CoV-2 antibody titer relation with the components of cellular immunity (CD3(+) cells and CD8(+)/CD38(+) ratio) shows a role of both chains during the response to the anti-SARS-CoV-2 vaccine in kidney transplant patients.