RESUMO
BackgroundIn October 2020, the National Cancer Institute (NCI) Serological Sciences Network (SeroNet) was established to study the immune response to COVID-19, and "to develop, validate, improve, and implement serological testing and associated technologies." SeroNet is comprised of 25 participating research institutions partnering with the Frederick National Laboratory for Cancer Research (FNLCR) and the SeroNet Coordinating Center. Since its inception, SeroNet has supported collaborative development and sharing of COVID-19 serological assay procedures and has set forth plans for assay harmonization. MethodsTo facilitate collaboration and procedure sharing, a detailed survey was sent to collate comprehensive assay details and performance metrics on COVID-19 serological assays within SeroNet. In addition, FNLCR established a protocol to calibrate SeroNet serological assays to reference standards, such as the U.S. SARS-CoV-2 serology standard reference material and First WHO International Standard (IS) for anti-SARS-CoV-2 immunoglobulin (20/136), to facilitate harmonization of assay reporting units and cross-comparison of study data. ResultsSeroNet institutions reported development of a total of 27 ELISA methods, 13 multiplex assays, 9 neutralization assays, and use of 12 different commercial serological methods. FNLCR developed a standardized protocol for SeroNet institutions to calibrate these diverse serological assays to reference standards. ConclusionsSeroNet institutions have established a diverse array of COVID-19 serological assays to study the immune response to SARS-CoV-2 virus and vaccines. Calibration of SeroNet serological assays to harmonize results reporting will facilitate future pooled data analyses and study cross-comparisons.
RESUMO
SARS-CoV-2 is locked in a high-stakes arms race between the dynamics of rising population immunity and escape mutations. The E484K mutation in the spike protein reduces neutralization by post-vaccination sera and monoclonal antibody therapeutics. We detected the emergence of an E484K harboring variant B.1.243.1 from a common circulating variant (B.1.243) in the United States. In contrast to other instances when the E484K mutation was acquired independently in the parental lineage, genomic surveillance indicates that the B.1.243.1 variant of interest is in the process of being established in Arizona and beginning to cross state borders to New Mexico and Texas. Genomic, epidemiologic and phylogenetic evidence indicates that the B.1.243.1 variant of interest is poised to emerge. These findings demonstrate the critical need to continue tracking SARS-CoV-2 in real-time to inform public health strategies, diagnostics, medical countermeasures and vaccines.
