ABSTRACT
The clinical outcomes in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection include asymptomatic disease or mild disease with influenza-like symptoms or severe disease condition following death by pneumonia and acute respiratory distress syndrome (ARDS). The current mRNA- and vector-based vaccines successfully addressed the antigenic challenges of the parental SARS-CoV-2 strain. However, recent concerns are being raised against some SARS-CoV-2 variants, which have the potential to escape natural immunity and vaccine-induced immune recognition partially, leading to a possible increase in transmissibility and disease severity. The coronavirus disease-19 (COVID-19)-induced rapid changes in human immune profiles might be instigating the evolution of SARS-CoV-2 with a higher propensity. Therefore, we require critical surveillance on the genomic sequence and structural conformation of the evolving variants and phenotypic impacts of the accumulating mutations on the host-immune response for possible updates in the booster vaccine sequence, if required. Here, we will highlight the role of accumulating mutations in SARS-CoV-2 genomic sequences leading to the host-immune escape by regulating the T cell- and B cell-mediated responses in infected, unvaccinated, and vaccinated individuals. © 2023 Elsevier Inc. All rights reserved.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and its resulting disease, coronavirus disease 2019 (COVID-19), has spread to millions of people worldwide. Preliminary data from organ transplant recipients have shown reduced seroconversion rates after the administration of different SARS-CoV-2 vaccination platforms. However, it is unknown whether different vaccination platforms provide different levels of protection against SARS-CoV-2. To answer this question, we prospectively studied 431 kidney and liver transplant recipients (kidney: n = 230; liver: n = 201) who received either the ChAdOx1 vaccine (n = 148) or the BNT-162b2 vaccine (n = 283) and underwent an assessment of immunoglobulin M/immunoglobulin G spike antibody levels. The primary objective of the study is to directly compare the efficacy of two different vaccine platforms in solid organ transplant recipients by measuring of immunoglobulin G (IgG) antibodies against the RBD of the spike protein (anti-RBD) two weeks after first and second doses. Our secondary endpoints were solicited specific local or systemic adverse events within 7 days after the receipt of each dose of the vaccine. There was no difference in the primary outcome between the two vaccine platforms in patients who received two vaccine doses. Unresponsiveness was mainly linked to diabetes. The rate of response after the first dose among younger older patients was significantly larger; however, after the second dose this difference did not persist (p = 0.079). Side effects were similar to those that were observed during the pivotal trials.