Effective presence of antibodies against common human coronavirus in IgG immunoglobulin medicinal products

Díez, José María; Romero, Carolina; Gajardo, Rodrigo

Introduction In this series of studies, immunoglobulin products (IgG) formulated for different routes of administration (IV, IM, SC) and prepared from geographically diverse plasma pools were tested for activity against common human coronaviruses (HCoV). IgG products from plasma obtained from Germany, Czech Republic, Slovak Republic, USA and Spain were tested for antibodies to four common HCoV: 229E, OC43, NL63 and HKU1. Since these products are manufactured from pooled plasma from thousands of donors, the antibodies therein are a representation of the HCoV exposure of the population at large. Methods IgG products of different concentrations manufactured from geographically diverse plasma pools were tested for antibodies to four common HCoV by ELISA. In addition, neutralization assays were conducted using HCoV-229E expressed in MRC5 cells. Complete concentration-neutralization curves were obtained to calculate potencies. Results The ELISA assays showed that when expressed as specific activity (anti-HCoV activity/mg IgG) similar activity against the four common HCoV was seen across the IgG products regardless of concentration or geographic origin. Highest anti-HCoV activity was seen against HCoV-229E, followed by HCoV-OC43 and then HCoV-NL63 and HCoV-HKU1. The neutralization assays showed similar potency for two preparations of IgG prepared by different processes. Conclusions These studies are the first demonstration of antibodies to common HCoV in IgG products. The level of activity was similar regardless of the geographic origin of the plasma pool. These antibodies demonstrated neutralization activity against HCoV-229E in MRC5 cells. These results may explain the cross-reactivity seen with pre-pandemic IgG products and SARS-CoV-2 and contribute to the variability in disease course in different patients.