Clinical trials are starting in hospitals in Argentina using a hyperimmune serum made with antibodies from horses, amid hopes it will reduce the severity of illness in those seriously ill with Covid-19.
The serum, developed in a collaborative effort, is obtained by injecting horses with a key SARS-CoV-2 protein.
The horses generate neutralizing antibodies, which are extracted in plasma, before being purified and processed.
Its backers say the hyperimmune serum has delivered promising results in laboratory testing.
It will now be used in nearly 250 volunteers across up to 15 Argentine hospitals, all of whom have been assessed with moderate to severe illness as a result of the Coronavirus infection.
Scientists who developed the serum hope it will slow the virus’s replication rate in sick individuals, lowering the viral load and effectively buying the patients’ time to allow their own bodies to mount an immune response.
Results from the trial are not expected until later this year.
The push is on around the globe to develop vaccines and treatments against the virus.
The public-private project in Argentina involves the Immunova laboratory, the Argentine Biological Institute, the National Administration of Laboratories and Health Institutes, the Leloir Institute Foundation, Mabxience, CONICET and the National University of San Martín.
The hyperimmune serum aims to produce what is known as passive immunisation. Antibodies given to patients work against the infectious agent, limiting its spread.
For the research, scientists identified a key protein crucial to allowing the coronavirus to enter cells. The protein is part of the so-called “spikes” on the outside of the virus.
Horses injected with the protein mounted a strong immune response.
Scientists are reported as saying that the horses are not affected at all by the extraction of the antibodies, in a process similar to plasmapheresis. This is where antibodies are separated and extracted before the blood is returned to the horse.
Researchers noted that a similar product developed for another disease proved to have a good safety profile. Serum with equine antibodies has been used successfully and safely to treat other infections.
Longer term, it is envisaged the hyperimmune serum could be given to those testing positive early in the disease, with a priority given to those at greatest risk of serious illness.