RIO DE JANEIRO, BRAZIL – On Thursday, August 13th, Brazilian scientists announced a new finding in a National Academy of Medicine session. Horses were administered the Sars CoV-2 Spike protein, responsible for human cell infection, and developed a 20 to 50 times more powerful neutralizing antibody against Covid-19.
Jerson Lima Silva, researcher at the Federal University of Rio de Janeiro (UFRJ) and president of the Carlos Chagas Filho Amparo Research Foundation of Rio de Janeiro (FAPERJ), and Adilson Stolet, physician and president of the Vital Brazil Institute (IVB), applied for the technology’s patent.
“This patent step is important. Everything has been developed here in Brazil and it is essential to protect this intellectual property,” Silva said in an interview.
The UFRJ researcher said the next step will be the approval of human clinical trials to determine the safety of a serological treatment against Covid-19. He said he is in contact with the National Health Regulatory Agency (ANVISA) and explained that the 50 times greater antibody power in horses is a conservative figure.
“We found antibodies up to 100 times more powerful in experiments. We monitored five horses weekly and four of them had a response even higher than 50.”
The study:
- The coronavirus has a crown-shaped protein, the Spike, through which the virus binds to human cell receptors in order to multiply;
- The Alberto Luiz Coimbra Institute of Post-Graduate Studies and Engineering Research (Coppe/UFRJ) produced a protein equal to that of Sars CoV-2 and took part in the research;
- The IVB specialists inoculated only the protein in horses – which produces an immune response, but does not allow the virus to infect the animals;
- Six ministrations were performed on the animals and the researchers monitored the production of antibodies on a weekly basis;
- Blood was collected from the horses and purified to isolate only the antibody, in a product ready for serotherapy in humans;
- The research is in the pre-printing stage, disclosed in a platform of scientific studies, but still unpublished by journals, and without peer review.
This type of serology treatment has been used for decades in diseases such as rabies, tetanus, and bee stings and snake bites. According to Silva, the best stage of coronavirus infection for the administration of neutralizing antibodies in humans still requires an answer, but he believes it will be in moderate and hospitalized patients.
“What is the advantage of horses? For instance, in the case of rabies, a single horse produces 600 vials of immunoglobulin for treatment,” he said.
The researcher further said clinical trials could be conducted in partnership with the D’Or Institute, which today leads AstraZeneca and Oxford University’s coronavirus vaccine research in Rio de Janeiro.
Plasma vs. isolated antibodies
On Tuesday, August 11th, the Pan American Health Organization (PAHO) alerted that blood plasma treatment with Covid-19 antibodies has no scientifically proven benefits. However, this type of treatment is different from what is being designed by the UFRJ, IVB, and Fiocruz.
PAHO director Sylvain Aldighieri explained that blood plasma treatment with antibodies against a given virus is used for some diseases, such as Ebola, in Africa. In the case of the coronavirus, however, as there is still no scientific evidence, PAHO does not recommend it.
“[Plasma treatment] is not part of the main treatment for Covid-19 we in PAHO are recommending,” explained Aldighieri, recalling that there is still no drug and proven treatment against the virus.
- Plasma: Plasma is the liquid part of the blood, where the antibodies produced by the body to fight diseases are stored. This substance, taken from recovered patients, can be administered to someone infected with Covid; however, each sample will have a different antibody amount and composition, because it depends on the donor’s body, and may not be effective.
- Neutralizing antibodies: Scientists isolate only the antibody that can neutralize the particular coronavirus. The product will consist of a small vial with only the antibody against the disease, while the plasma contains all the antibodies, varying in composition.
Source: G1