Scientists say they have found the strongest antibodies to date in the blood of patients with Covid-19, raising hopes that people will develop immunity to the virus.
The antibodies were taken from the blood of several survivors of Covid-19 and can neutralize the coronavirus, preventing it from entering cells.
These antibodies are cloned and scaled in large quantities in the laboratory before being injected as treatment.
Experts have discovered a cocktail of extremely potent antibodies that protected hamsters from Covid-19 when exposed to the SARS-CoV-2 virus.
These are only preliminary findings, but scientists say antibodies – substances used by the immune system to destroy viruses – are “ready to be developed into treatments.”
Administered in doses like a vaccine, scientists say the antibodies could give humans the ability to avoid being struck by the disease.
Antibodies made in the lab to mimic natural antibodies have been used in the treatment of a wide range of conditions, including arthritis, Crohn’s disease, and Ebola virus.
Scientists claim they have discovered the strongest antibodies to Covid-19 ever found that may protect against infection (stock image)
Antibodies are proteins produced by the immune system in response to the presence of a foreign substance, such as coronavirus.
The role of antibodies is to cling to foreign substances like the coronavirus and tag it for other immune cells, such as T cells, to kill them.
Neutralizing antibodies are able to kill the virus on their own, rather than just tagging it for other immune cells to attack.
David Ho, scientific director of the Aaron Diamond Aids Research Center and professor of medicine at Columbia University Vagelos College of Physicians and Surgeons, led the study.
He said, “We now have a collection of more potent and more diverse antibodies compared to other antibodies found so far, and they are ready to be developed into treatments. “
WHAT IS MONOCLONAL ANTIBODY THERAPY?
Monoclonal antibody therapy is a form of immunotherapy that uses monoclonal antibodies (mAbs).
It is given by injection under the skin or by drip into a vein.
The treatment works in different ways. It can work like a vaccine, protecting a patient against serious illness or can help stimulate the patient’s immune system to attack the antigens.
Hybridoma technology is a method of producing a large number of monoclonal antibodies – identical antibodies that are clones of a single mother cell.
The process begins by injecting an animal, such as a mouse, with an antigen that elicits an immune response.
B cells produce antibodies that bind to the antigen. These antibody-producing B cells are then harvested and used to grow more antibodies.
Monoclonal antibodies are screened against their ability to act, with initial animal experiments.
Major technological advances have made the discovery and development of mAb therapies faster and more effective, deriving antibodies from humans and not from animals.
Scientists can create a mAb specific for almost any antigens and are working on one for the coronavirus.
The spike protein on the SARS-CoV-2 virus is the main target explored for potential Covid-19 monoclonal antibodies.
The goal is that by targeting the spike protein, the antibody can neutralize the SARS-CoV-2 virus, preventing it from infecting healthy cells.
A particularly interesting avenue is to give them to people who are not yet infected as a prevention tool. If the antibodies are strong and long-lasting enough, they could provide sufficient protection for some time before a vaccine is found.
Research and development is underway to create antibodies against diseases such as rheumatoid arthritis, multiple sclerosis, Alzheimer’s disease, and different types of cancers.
But many are already in use in the US and UK.
Since 2008, 48 new mAbs have been approved, contributing to a total global market of 61 mAbs in clinical use at the end of 2017, according to the US FDA.
Forty Covid-19 patients who were treated at Irving Medical Center at Columbia University in New York City, but who have since recovered, were recruited for the research.
Blood samples from all of them were first tested for their neutralizing activity against the virus. Scientists put their blood in a Petri dish to see if the antibodies attack or bind to the virus.
The team saw a wide array of neutralizing antibodies, but focused on five patients whose plasma had the highest levels of neutralizing antibodies.
The five patients have all been hospitalized with Covid-19, suggesting that those with severe illness requiring mechanical ventilation produce the best neutralizing antibodies.
Among them, 19 neutralizing antibodies that “exhibited exquisite potency” were discovered, according to results published in the journal Nature.
Professor Ho said: “We believe that the sicker patients saw more virus and for a longer period of time, which allowed their immune systems to develop a more robust response.
“This is similar to what we have learned from the experience of HIV.
The research team found a more diverse variety of antibodies than previous efforts, including new unique antibodies that had not been reported before.
The results also revealed which sites on the virus’ outer “peak” are the most vulnerable.
Professor Ho said, “Using a cocktail of different antibodies directed at different peak sites will help prevent the virus from becoming resistant to treatment. “
The researchers took the neutralizing antibodies and modified them in the lab to create monoclonal antibodies (mAbs) – clones that work similarly to natural antibodies.
To assess whether they were working, the researchers exposed hamsters to the coronavirus after an injection of mAbs.
Hamster lung tissue was taken to quantify the viral load four days later.
Hamsters given a higher dose of mAb had considerably less virus particles than those given a low dose as a control group.
The researchers said there was “a complete elimination of infectious SARS-CoV-2 at a relatively modest dose of antibody.”
Professor Ho hopes the results will lead to treatment in humans, which would require clinical trials first to ensure safety.
It’s unclear how long this would take, but it could be faster than a number of drugs and vaccines in development for Covid-19.
The development and approval of antibodies for use as a treatment generally takes less time than conventional drugs.
Scientists around the world are studying monoclonal antibody therapy for the new coronavirus, but there are few currently in clinical trials.
Last month, researchers at Scripps Research in San Diego also claimed to have discovered super strong antibodies that protect animals from serious disease.
Drug giant AstraZeneca has also revealed that it is working on an injection of cloned antibodies that could be ready next year.
Managing Director Pascal Soriot told the Sunday Telegraph that the current therapy was “a combination of two antibodies” in an injected dose.
The discovery of super potent antibodies also bodes well for vaccine development, scientists say.
If the immune system can generate such powerful antibodies, vaccines that do the same “should provide robust protection against the virus,” Professor Ho said.
However, questions remain as to whether Covid-19 survivors develop immunity once they recover from the disease.
Therefore, it will not be clear how long the produced antibodies triggered by a vaccine would protect a person.