Publications & Presentations

Implications for sourcing COVID-19 convalescent plasma from routinely collected blood donations

Authors

Clara Di Germanio ^1 2, Xutao Deng ^1 2, Brendan G Balasko ¹, Graham Simmons ^1 2, Rachel Martinelli ¹, Eduard Grebe ¹, Mars Stone ^1 2, Bryan R Spencer ³, Paula Saa ⁴, Elaine A Yu ^1 2, Marion C Lanteri ^2 5, Valerie Green ⁵, David Wright ⁶, Isaac Lartey ⁶, Steven Kleinman ⁷, Jefferson Jones ⁸, Brad J Biggerstaff ⁹, Paul Contestable ¹⁰, Michael P Busch ^1 2

Abstract

Background: COVID-19 convalescent plasma (CCP) remains a treatment option for immunocompromised patients; however, the current FDA qualification threshold of ≥200 BAU/mL of spike antibody appears to be relatively low. We evaluated the levels of binding (bAb) and neutralizing antibodies (nAb) on serial samples from repeat blood donors who were vaccinated and/or infected to inform criteria for qualifying CCP from routinely collected plasma components.

Methods: Donors were categorized into four groups: (1) infected, then vaccinated, (2) vaccinated then infected during the delta, or (3) omicron waves, (4) vaccinated without infection. IgG Spike and total Nuclecapsid bAb were measured, along with S variants and nAb titers using reporter viral particle neutralization.

Results: Mean S IgG bAb peaks after infection alone were lower than after primary and booster vaccinations, and higher after delta and omicron infection in previously vaccinated donors. Half-lives for S IgG ranged from 34 to 66 days after first infection/vaccination events and up to 108 days after second events. The levels of S IgG bAb and nAb were similar across different variants, except for omicron, which were lower. Better correlations of nAb with bAb were observed at higher levels (hybrid immunity) than at the current FDA CCP qualifying threshold.

Discussion: Routine plasma donations from donors with hybrid immunity had high S bAb and potent neutralizing activity for 3-6 months after infection. In donations with high (>4000 BAU/mL) S IgG, >95% had high nAb titers (>500) against ancestral and variant S, regardless of COVID-19 symptoms. These findings provide the basis for test-based criteria for qualifying CCP from routine blood donations.

Keywords: immunology (other than RBC serology); infectious disease testing.

Affiliations

• ¹Vitalant Research Institute, San Francisco, California, USA.
• ²Department of Laboratory Medicine, University of California San Francisco, San Francisco, California, USA.
• ³American Red Cross, Scientific Affairs, Dedham, Massachusetts, USA.
• ⁴American Red Cross, Scientific Affairs, Rockville, Maryland, USA.
• ⁵Creative Testing Solutions, Tempe, Arizona, USA.
• ⁶Westat, Rockville, Maryland, USA.
• ⁷University of British Columbia, Victoria, British Columbia, Canada.
• ⁸Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
• ⁹Centers for Disease Control and Prevention, Fort Collins, Colorado, USA.
• ¹⁰Ortho Clinical Diagnostics, Rochester, New York, USA.

© 2024 The Author(s). Transfusion published by Wiley Periodicals LLC on behalf of AABB. This is an open access article under the terms of the Creative Commons Attribution-Non Commercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.