Evaluation and Characterization of SARS-CoV-2 Antibody in Convalescent Volunteer Plasma Donors for Potential Therapeutic Use

This project focused on an analysis of antibody response to SARS-CoV-2 with an emphasis on how best to enroll those from medically underserved areas. The study was coordinated from the City of Hope (COH) and, in an attempt to capture a wide range of persons who had recovered from COVID-19, it involved investigators and patients from COH, UC Irving, UC San Diego, Huntington Memorial Hospital Pasadena, and a pulmonary medicine clinic in Ventura County. The study used antibody measurements of three types, measuring standard SARS-CoV-2 surface (spike) antibodies, virus neutralization antibodies, and peptide specific antibodies.  The following was observed:

• The use of three antibody assays which measured total antibody, virus inhibition antibody, called neutralization antibody, and peptide-specific antibody correlated well for the characterization of COVID-19 convalescent plasma (CCP)
• Neutralization antibody persisted longer than IgM/IgG antibodies.
• Among participants from health and healthcare-disparate areas, those with primary care-disparity developed significantly higher antibodies, both total and neutralizing antibodies. This is a hypothesis generating observation that deserves further analysis.
• Vaccination of those with prior SARS-CoV-2 infection induced the highest antibody and removed any difference among ethnic or health-disparity groups.

These observations have public health implications and confirm that the use of vaccine, even after natural COVID-19 illness, is important to provide high protective antibody and can last for months.