Background
Through a joint effort in 2020, the Coalition for Epidemic Preparedness Innovations (CEPI), the National Institute for Biological Standards and Control (NIBSC), and the World Health Organization (WHO) provided COVID-19 vaccine developers and the entire scientific community with a research reagent for an anti-SARS-CoV-2 antibody, an International Reference Panel and the first WHO International Antibody Standard for assay calibration (https://www.who.int/news-room/feature-stories/detail/standardization-of-vaccines-for-coronavirus-disease-covid-19). These materials are constituted of plasma samples sourced from SARS-CoV-2 convalescent patients.
The emergence of SARS-CoV-2 variants which appear to be serologically diverse from the original VIC-01 isolate has raised questions on the suitability of current assays, the efficacy of candidate vaccines, and the suitability of WHO-endorsed International Standard established in December 2020.