Background: Antibody dependent enhancement (ADE) is a unique immunopathological phenomenon in which pre-existing immunity to a viral agent accentuate disease severity upon secondary exposure. Multiple viruses have been shown to demsotrate ADE with no clear understanding of the underlying mechansims. Recently, with the emeregence of Sever acute respiratory syndrome-2 (SARS-CoV2) and the need for rapid vaccine prodcution, ADE have emerged as an important issue that need to be assessed. Objective: The aim of this study was to review ADE, proposed mechanisms and impact of ADE in the era of rapid SARS-CoV2 vaccine production. Methods: Review of existing published literature on ADE and SARS-CoV2 and identify facts that support or otherwise contradict the impact of ADE on SARS-CoV2 vaccination. Results: SARS-CoV2 demonstrate high genetic homology to other members of the Coronaviridae viral family and animal studies and studies on SARS-CoV, another member of the Coronaviridae have been shown to induce ADE. In addition sever SARS-CoV2 infection have been associated with high antibody titer. Yet vaccine efficacy studies and studies on breakthrough infection showed reduced severity in individual with preexisting immunity Conclusion: Although evidence exist to support ADE in SARS-CoV2, multiple studies do not support its occurrence, indicating the need for more case control studies to understand the role of high antibody titer and disease severity and compare disease severity in patient with preexisting immunity vs naïve individuals.
Key words: Enhancement, SARS-CoV2, vaccine, intrinsic, extrinsic.
|
