Antibody responses to SARS-CoV-2 spike protein in a cohort of renal transplant recipients following two-dose primary immunization − A Caribbean country’s perspective

This study compares the humoral immune response of a cohort of renal transplant recipients (RTRs), in Trinidad & Tobago following two-dose primary immunization with non-mRNA vaccines amidst the COVID-19 pandemic. RTRs along with healthy, age-and gender-matched controls received either the adenoviral vector vaccine, AstraZeneca-Vaxzevria (AZ) or the inactivated vaccine, Beijing CNBG-BBIBP- CorV/Sinopharm (SP). Samples were taken after completion of a two-dose primary immunization during the period November 2021 to December 2021, at a mean interval of 138 days following immunization. 38/72 RTRs (53 %) failed to generate any protective antibody responses, compared with 7/73 participants, approximately 10 % in the healthy, age and gender-matched control group. In the RTRs, there was no significant correlation of their antibody concentration with either the timing of sample collection or the interval since transplantation. The study provides necessary information about the humoral response after two- doses of non-mRNA vaccines in a group of transplant recipients.