History repeats itself: horse originated hyperimmune sera production against SARS CoV-2

Abstract

Background/aim: SARS-CoV-2 disease was announced as a pandemic by The World Health Organization in on early 2020. It is still threatening the world population. Here, we aimed to produce hyperimmune sera that contain immunoglobulin G and F(ab')2 fragments sourced from horse antibodies as an urgent response to the pandemic.Materials and methods: SARS-CoV-2 was produced and inactivated with three different methods [formaldehyde (FA), formaldehyde, and binary ethylene amine (FA+BEI), and heat treatment]. After invitro in vitro inactivation control, immunogens were mixed with Freund's adjuvant, thereafter horses (n: 2 for FA, 4 for FA + BEI, 2 for Heat inactivation) and New Zealand rabbits (n: 6 for FA, 6 for FA + BEI, 6 for Heat inactivation) were immunized four times. Neutralizing antibody levels of the sera were measured at the 4 th , 6 th , and 8 th weeks. When the antibodies were detected at the peak level, plasma was collected from horses and hyperimmune sera procured after the purification process.Results: Horses and rabbits produced highly neutralizing antibodies against the SARS-CoV-2 in FA and FA + BEI inactivation groups, foreign proteins were removed effectively after purification. Conclusion:This study presents a profitable practice to develop horse-specific antisera against SARS-CoV-2 for emergency and low-cost response. In further studies, new purification methods can be used to increase the efficiency of the final product.

Development of Equine Polyclonal Antibodies as a Broad-Spectrum Therapy Against SARS-CoV-2 Variants

“…Equine antibodies, as mature antibody therapeutics, can overcome these limitations. Their safety has been recognized for ages by World Health Organization over several widespread diseases (31). In this paper, our results…”

“…Equine antibodies, as mature antibody therapeutics, can overcome these limitations. Their safety has been recognized for ages by World Health Organization over several widespread diseases(31). In this paper, our results showed the possibilities of using horse immunization to generate anti-RBD pAbs with excellent neutralization activities against several wide spread SARS-CoV-2 variants including Delta, BA.1 and BA.2, on top of WT.…”

Neutralization of Different Variants of SARS-CoV-2 by a F(ab′)2 Preparation from Sera of Horses Immunized with the Viral Receptor Binding Domain

“…Equine F(ab )2 preparation produced by immunization with the whole inactivated virus proved to bind to wildtype and all the VOCs RBD by surface plasmon resonance experiments [23]. However, similar reductions in the neutralization ability against the different viral VOCs were observed, irrespective of the antigen used for immunization, i.e., when using the whole inactivated virus [24] or the S protein [26]. None of these studies evaluated the neutralization of their biological preparation against the Mu VOI.…”

“…The production of equine sera against venoms of snakes and scorpions, but also against several infectious agents, laid the foundations for producing an anti-SARS-CoV-2 equine serum [23][24][25][26][27][28]. Several viral antigens have been evaluated for the production of this biological: inactivated SARS-CoV-2 whole virus [23,24], S [25], or RBD [26][27][28].…”

“…The production of equine sera against venoms of snakes and scorpions, but also against several infectious agents, laid the foundations for producing an anti-SARS-CoV-2 equine serum [23][24][25][26][27][28]. Several viral antigens have been evaluated for the production of this biological: inactivated SARS-CoV-2 whole virus [23,24], S [25], or RBD [26][27][28]. A living systematic review of randomized controlled trials suggests that RBD-specific polyclonal F(ab )2 fragments of equine antibodies may reduce mortality and serious adverse events and may reduce clinical worsening, at least before widespread vaccination against this virus [29].…”