Currently antibody testing for COVID-19 requires serum or plasma obtained by venipuncture. But researchers in the United Kingdom are hopeful widespread testing for immunity against Covid-19 can be accomplished from fingerstick blood---even samples collected by patients themselves---onto filter paper similar to that used for newborn screening. 

Researchers in Birmingham, United Kingdom collected blood samples from 80 healthy volunteers, and 31 who had previously tested positive for Sars-CoV-2 antibodies. All patients were anonymized and collected by fingerstick for dried blood spot testing and by venipuncture for molecular testing (PCR). Results correlated significantly giving the researchers confidence that immunity to Covid-19 can be reliably determined from patient-collected samples. After analyzing their data, dried blood spot samples demonstrated 98% sensitivity and 100% specificity for detecting anti-SARS-CoV-2 S glycoprotein antibodies. A full 100% of the PCR-positive serum samples were also antibody-positive as dried blood spots.

If implemented on a wide scale, dried blood spots collected by the patient and shipped or delivered in person to a testing facility could substantially impact global control of the pandemic, especially in rural areas and resource-limited countries. With widespread high volume testing of self-collected samples, patient contact would be unnecessary, exposure prevented, and the risks of venipuncture eliminated.

Read the full study.

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