P16.06: Seroconversion in Pacients After SARS-Cov-2 CHADOX1 NCoV-19/AZD1222 Vaccination in Hemodialysis Patients And Kidney Transplant Recipients

Background: Since December 2019 the world has been affected for Coronavirus SARS-CoV-2 pandemic. In Aguascalientes state at March 13th 2022 has been confirmed a total of 62,440 cases and 3,479 deaths caused by COVID-19. As a combat strategy were developed different kind of vaccines against SARS-CoV-2. The Oxford University developed the vaccine ChAdOx1 nCov-19/AZD1222 which is based in a viral vector which codes the information of the spike protein of SARS-CoV-2. It has been proven that the morbidity and mortality from COVID-19 is higher in hemodialysis (HD) patients and Kidney Transplant (KT) recipients. Objective: Measure and compare the seroconversion level in hemodialysis patients and kidney transplant recipients (KTR), who received two doses of the ChAdOx1 nCov-19/AZD1222 vaccine and identify the factors associated with low response to the vaccine used in our study population. Methods: We performed a prospective, observational, unblinded and comparative analysis. Patients included between 18-80 years old, both genders, that they were in HD or with KTR, and received two doses of the ChAdOx1 nCov-19/AZD1222 vaccine between 2-6 months before sampling. The antibodies level against spike protein of SARS-CoV-2 was determined by the immunoassay Elecsys anti-SARS-CoV-2 and we determined a positive result ≥100 U/mL. Statistical Analysis: iChi2 test with Yates´ correction, Student´s T-Test unpaired and multiple logistic analysis. p<0.05 was considered as significant. Results: 67 patients were included, 49 in HD and 18 with KTR. In the multiple logistic regression analysis, taking the positive seroconversion ≥100 U/mL as the dependent variable, the KT was the risk factor associated with a lower seroconversion frequency, p<0.05 Exp(B) 3.26. Conclusions: The ChAdOx1 nCov-19/AZD1222 vaccine was associated with a higher seroconversion level in HD patients in comparison to KTR. The KTR patients presented a higher frequency of SARS-COV2 infection post vaccination in relation to HD patients. The main risk factor associated with lower seroconversion response was KT in patients who received the ChAdOx1 nCov-19/AZD1222 vaccine. Our population presented a higher seroconversion response that reported in the literature, probably because of the SARS-COV2 infection antecedent prior to vaccination.