Analysis of SARS-CoV-2 Antibodies in COVID-19 Convalescent Plasma using a Coronavirus Antigen Microarray

Rafael R. de Assis; Aarti Jain; Rie Nakajima; Algis Jasinskas; Jiin Felgner; Joshua M. Obiero; Oluwasanmi Adenaiye; Sheldon Tai; Filbert Hong; Philip Norris; Mars Stone; Graham Simmons; Anil Bagri; Martin Schreiber; Andreas Buser; Andreas Holbro; Manuel Battegay; Donald K. Milton; Huw Davies; Laurence M. Corash; Michael P. Busch; Philip L. Felgner; Saahir Khan

The SARS-CoV-2 convalescent blood specimens from nasopharyngeal SARS-CoV-2 PCR-positive individuals were collected from different sources to increase the number of positive specimens available for analysis. Two sera and plasma samples were obtained from acute COVID-19 patients from the Oregon Health Sciences University Hospital (OHSU), Portland, OR. These were sourced from discarded clinical laboratory specimens exempted from informed consent and IRB approval under condition of patient anonymity. Four plasma samples were obtained from outpatients of the University Hospital Basel, University of Basel, Basel, Switzerland. These patients were screened in accordance with Swiss regulations on blood donation and approved as plasma donors according to the Blood Transfusion Service of the Swiss Red Cross with informed consent. These donors were diagnosed with COVID-19 based on SARS-CoV-2 positive nasopharyngeal swab PCR tests. At time of plasma donation, each had two negative nasopharyngeal swab SARS-CoV-2 PCR-tests and negative SARS-CoV-2 PCR tests in blood, and they were qualified as plasma donors. Plasma was collected from these convalescent donors at the Regional Blood Transfusion Service of the Swiss Red Cross in accordance with national regulations. One convalescent plasma was isolated from a large-volume apheresis collection following standard protocol from a documented recovered COVID-19 blood donor who was more than 28 days post symptomatic. The negative control sera used in this study were collected between November 2018 and May 2019 for a larger study where residents of a college resident community in the Eastern United States were monitored prospectively to identify acute respiratory infection (ARI) cases using questionnaires and RT-qPCR, so as to characterize contagious phenotypes including social connections, built environment, and immunologic phenotypes 12 . A total of 144 de-identified blood specimens were tested on the CoV antigen microarray. Electronic informed consents including future research use authorization was obtained under protocols approved by the Institutional Review Boards (IRBs) of the University of Maryland and the Department of Navy Human Research Protections Office.