High Efficacy of Therapeutic Equine Hyperimmune Antibodies Against SARS-CoV-2 Variants of Concern

Andres Moreira-Soto; Mauricio Arguedas; Hebleen Brenes; Willem Buján; Eugenia Corrales-Aguilar; Cecilia Díaz; Ann Echeverri; Marietta Flores-Díaz; Aarón Gómez; Andrés Hernández; María Herrera; Guillermo León; Román Macaya; Arne Kühne; José Arturo Molina-Mora; Javier Mora; Alfredo Sanabria; Andrés Sánchez; Laura Sánchez; Álvaro Segura; Eduardo Segura; Daniela Solano; Claudio Soto; Jennifer L Stynoski; Mariángela Vargas; Mauren Villalta; Chantal B E M Reusken; Christian Drosten; José María Gutiérrez; Alberto Alape-Girón; Jan Felix Drexler

doi:10.3389/fmed.2021.735853

High Efficacy of Therapeutic Equine Hyperimmune Antibodies Against SARS-CoV-2 Variants of Concern

Front Med (Lausanne). 2021 Sep 6:8:735853. doi: 10.3389/fmed.2021.735853. eCollection 2021.

Authors

Andres Moreira-Soto^{1

2}, Mauricio Arguedas³, Hebleen Brenes⁴, Willem Buján^{5

6}, Eugenia Corrales-Aguilar², Cecilia Díaz^{3

5}, Ann Echeverri⁶, Marietta Flores-Díaz³, Aarón Gómez³, Andrés Hernández³, María Herrera³, Guillermo León³, Román Macaya⁶, Arne Kühne¹, José Arturo Molina-Mora², Javier Mora², Alfredo Sanabria⁶, Andrés Sánchez³, Laura Sánchez³, Álvaro Segura³, Eduardo Segura³, Daniela Solano³, Claudio Soto⁴, Jennifer L Stynoski³, Mariángela Vargas³, Mauren Villalta³, Chantal B E M Reusken⁷, Christian Drosten¹, José María Gutiérrez³, Alberto Alape-Girón^{3

5}, Jan Felix Drexler^{1

8}

Affiliations

¹ Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
² Centro de Investigación en Enfermedades Tropicales (CIET), Facultad de Microbiología, Universidad de Costa Rica, San Jose, Costa Rica.
³ Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San Jose, Costa Rica.
⁴ Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud, Ministry of Health, Tres Ríos, Costa Rica.
⁵ School of Medicine, Universidad de Costa Rica, San Jose, Costa Rica.
⁶ Caja Costarricense del Seguro Social, San Jose, Costa Rica.
⁷ Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, Netherlands.
⁸ German Centre for Infection Research (DZIF), Associated Partner Charité-Universitätsmedizin Berlin, Berlin, Germany.

Abstract

SARS-CoV-2 variants of concern show reduced neutralization by vaccine-induced and therapeutic monoclonal antibodies; therefore, treatment alternatives are needed. We tested therapeutic equine polyclonal antibodies (pAbs) that are being assessed in clinical trials in Costa Rica against five globally circulating variants of concern: alpha, beta, epsilon, gamma and delta, using plaque reduction neutralization assays. We show that equine pAbs efficiently neutralize the variants of concern, with inhibitory concentrations in the range of 0.146-1.078 μg/mL, which correspond to extremely low concentrations when compared to pAbs doses used in clinical trials. Equine pAbs are an effective, broad coverage, low-cost and a scalable COVID-19 treatment.

Keywords: COVID-19; PRNT titers 50; SARS-CoV-2; equine antibodies; neutralization test; therapy; variant of concern.

Copyright © 2021 Moreira-Soto, Arguedas, Brenes, Buján, Corrales-Aguilar, Díaz, Echeverri, Flores-Díaz, Gómez, Hernández, Herrera, León, Macaya, Kühne, Molina-Mora, Mora, Sanabria, Sánchez, Sánchez, Segura, Segura, Solano, Soto, Stynoski, Vargas, Villalta, Reusken, Drosten, Gutiérrez, Alape-Girón and Drexler.