Serum anti‐Spike immunoglobulin G levels in random blood donors in Italy: High‐titre convalescent plasma is easier than ever to procure
Daniele Focosi, Silvia Meschi, Sabrina Coen, Maria Carla Iorio, Massimo Franchini, Maria Lanza, Fabrizio Maggi - Hematology
- General Medicine
Abstract
Background and Objectives
COVID‐19 convalescent plasma (CCP) has retained potency and clinical efficacy against SARS‐CoV‐2 and is currently of utmost value for seronegative immunocompromised patients. Since most of the effect is due to the vaccine boost of infection‐elicited antibodies, there is a theoretical concern that the frequency of suitable donors is declining.
Materials and Methods
In this single‐institution serosurvey, we screened 599 consecutive donors attending our area in two different seasons (300 in November 2022 and 299 in February 2023) using the Abbott Alinity® anti‐Spike immunoglobulin G assay.
Results
More than 80% of random donors qualify according to the FDA criteria for high‐titre CCP (>4350 AU/mL), with a stable trend.
Conclusion
Despite reduced anti‐Spike vaccine boost deployment in the general population, we have shown here that high‐titre CCP units are easier than ever to procure. This finding also has implications for the derivation of standard immunoglobulins, which are finally approaching the potency of hyperimmune serum and could soon represent an alternative to CCP.