Remote fingerstick blood collection for SARS-CoV-2 antibody testing

The rapid worldwide spread of SARS-CoV-2 infection has propelled the rapid development of serological tests that can detect anti-SARS-CoV-2 antibodies. These have been used for studying the prevalence and spread of infection in different populations, helping establish a diagnosis of COVID-19, and will likely be used to confirm humoral immunity after infection or vaccination. However, nearly all lab-based high-throughput SARS-CoV-2 serological assays require a serum sample from venous blood draw, limiting their applications and scalability. Here, we present a method that enables large scale SARS-CoV-2 serological studies by combining self or office collection of fingerprick blood with an FDA-approved dried blood spot collection device (Neoteryx Mitra®) with a high-throughput electrochemiluminescence-based SARS-CoV-2 total antibody assay (Roche Elecsys®) that is EUA approved for use on serum samples and widely used by clinical laboratories around the world. We found that the Roche Elecsys® assay has a high dynamic range that allows for accurate detection of SARS-CoV-2 antibodies in serum samples diluted 1:20 as well as contrived dried blood extracts. Extracts of dried blood from Neoteryx Mitra® devices acquired in a community seroprevalence study showed near identical sensitivity and specificity in detection of SARS-CoV-2 antibodies as compared to neat sera using predefined thresholds for each specimen type. Overall, this study affirms the use of Neoteryx Mitra® dried blood collection device with the Roche Elecsys® SARS-CoV-2 total antibody assay for remote or at-home testing as well as large-scale community seroprevalence studies.