ABSTRACT
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.
ABSTRACT
ObjectiveOur objective is to estimate CoV-2 infection rates in a rural state using seroprevalence of antibodies to CoV-2 as an indicator of infection. Study Design and SettingThis is a single-site study within an academic center and regional programs within the state of Arkansas. We obtained residual serum samples from a convenience sample of adults who were outpatients and came to the hospital or regional clinic for non-COVID-related reasons. We collected remnant in three time periods (August 15 to September 5, September 12 to October 24, and November 7 to December 19). ResultsIn 2020, the overall age, gender, and race standardized prevalence of CoV-2 antibodies was 2.6% (August to September), 4.1% (September to October), and 7.4% (November to December). There was no difference in seroprevalence between urban compared to rural areas. Positive tests were not uniformly distributed across racial and ethnic minorities. Higher seroprevalence rates were found in Hispanics and Blacks or African Americans compared to whites across all time periods. ConclusionsIn a state with a large rural population, 2.6-7.4% of people experienced CoV-2 infection by December 2020. Blacks and Hispanics had disproportionately higher rates of CoV-2 infections than whites. What is new?O_ST_ABSKey findingsC_ST_ABSIn this prospective convenience sampling of remnant sera, we found increasing seroprevalence from 2.6% to 7.4% (August 2020 to December 2020). Higher seroprevalence rates were found in Hispanics and Blacks or African Americans compared to whites across all time periods, and no difference was determined between those individuals from rural or urban areas. What this adds to what is knownIn a largely rural population, Blacks and Hispanics had disproportionately higher rates of CoV-2 infections than whites, and these populations need to be studied further regarding outcomes. What is the implication?There are health disparities that exist regarding CoV-2 infections, and we should target vaccination information and education to these groups. Highlights- SARS-CoV-2 infections increased from 2.6% to 7.4% from August to December 2020. - Higher seroprevalence was found in Hispanics and Blacks as compared to whites. - There was no difference in the seroprevalence in rural compared to urban areas.