CONICET researchers make advances on the development of a therapeutic serum against COVID-19

An Argentine research team conducted in vitro tests of a therapeutic serum to treat patients infected with COVID-19 and proved the serum’s capacity of neutralizing virus SARS-CoV-2 in vitro test. It is the resulting work of public-private articulation led by Laboratorio Inmunova, the Instituto Biológico Argentino (BIOL), the ‘Administración Nacional de Laboratorios e Institutos de Salud “Dr. Carlos G. Malbrán” (ANLIS), the collaboration of CONICET, the Fundación Instituto Leloir (FIL), Mabxience and the Universidad Nacional de San Martín (UNSAM). This is a hyper immune serum anti-COVID-19 for passive immunization. With this promising result, Inmunova will soon start the phase of clinical trials in patients.

Passive immunization is to give patients antibodies against the infectious agent, blocking it and preventing it from spreading. This is how the serum works, which is similar to those used to treat snake and scorpion sting poisoning, tetanus toxin poisoning, exposure to rabies virus and infections such as avian influenza.

Fernando Goldbaum, CONICET researcher at the Centro de Rediseño e Ingeniería en Proteínas (CRIP, UNSAM) and founding partner and scientific director of Inmunova, explained: “Unlike vaccines (active immunization) which allow a person to preventively generate their own antibodies against certain pathogens, the therapeutic serum introduces antibodies from outside that can act quickly in a patient that is already infected. For instance, when we cut ourselves with a wire, the first thing doctors do is to give us an anti-tetanus serum and then the vaccine.”

Considering the emergence of the pandemic, passive immunotherapy represents one of the most promising therapeutic strategies being investigated in the world, to reduce the impact and lethality of the new coronavirus. The anti-COVID-19 serum is proposed as a treatment for patients diagnosed with the infection to be administered in the early stages of the disease. In its development, scientists used a recombinant virus protein as antigen to obtain polyclonal antibodies. The serum produced contains a large number of these antibodies with neutralizing capacity, which means that it could prevent the virus from entering the cells, the place where it multiplies.

To develop the therapeutic serum anti-COVID-19, Innmunova and the Instituto Nacional de Enfermedades Infecciosas (INEI-ANLIS) did some tests in their laboratories and the INEI-ANLIS isolated the virus and measured the neutralizing capacity of the serum. At the same time, the Fundación Instituto Leloir, Mabxience and researchers from CONICET and UNSAM developed of the recombinant protein for the tests.

As BIOL has decades of national and international experience in the production of hyper immune serums, it developed the serum engineering batches for pre-clinical and clinical tests, in its specialized plant, complying with the Good Manufacturing Practices standards for pharmaceutical products. It will be possible to produce there the serum to meet the needs of the whole country.

With extensive experience in engineering recombinant proteins, antibodies and research into hyper immune serums, Inmunova has a development program to work as quickly as the pandemic demands in compliance with the stages and scientific standards established for drug research. For this reason, from the beginning, it has interacted with the Administración Nacional de Medicamentos, Alimentos y Tecnología Médica (ANMAT) and advisory team that comprises renowned infectologists.

This project was one of the selected ones that were presented to the ‘National Agency of Promotion of Research, Technological Development and Innovation’ in response to the call ‘Ideas Project COVID-19’ of ‘Unit Coronovirus’ created by the Ministry of Science, Technology and Innovation –which comprises CONICET and the Agency.  

 “It is worth mentioning that this is first therapeutic product against Coronavirus SARS-CoV-2 entirely conducted in Argentina and by Argentine scientists. I would like to stress the importance of this public-private collaboration to make it possible,” the researcher says.

Characteristics of the new serum

Anti-COVID-19 serum has been developed for passive immunization, considering immunotherapy as probably the most effective way to attenuate the effects of the pandemic in the short and medium term.

In this sense, another passive immunization method is currently being analyzed, the application of convalescent plasma, which contains the antibodies generated by patients who recovered from the disease.

Although vaccines will be the ideal strategy in the long term, term, they imply long term work and availability.

The serum developed is based on equine polyclonal antibodies, which are obtained by injecting a recombinant SARS-CoV-2 protein in these animals harmless to them, which have the capacity to generate large number of antibodies that can neutralize the virus.

“This serum’s advantage with respect to the use of convalescent plasma –a strategy that we also support and has proved to be the safest and most effective– is if it works, its production can be scaled to also treat patients in early stages of the disease. It would be possible to produce it for all the population that needs it,” Goldbaum explains.