Although it is the Spring Festival holiday, but presumably everyone has not relaxed feeling, are closely watching the progress of the new coronavirus outbreak. With the further study of diagnosis and treatment techniques, more and more people infected with the virus have been announced from the hospital as the knowledge and experience of the virus become more and more abundant. This is probably the most news we want to hear these days about the outbreak.
It is precisely because more and more infected people are cured, but also some people put forward their own “treatment ideas” – the cure’s blood should already exist antibodies, can these healer’s blood pump out some directly to the infected person for treatment, or injection to the uninfected person for prevention to use it?
Part.1 It’s a coincidence that your thoughts and questions coincide with Bill Gates
In a TED speech, Bill Gates mentioned in response to the Ebola outbreak that one idea was to get the blood that healed the patient, treat it, and then inject it into the body for protection. He also raised his own confusion, how this method has never been tried?
Indeed, when pathogens such as viruses or bacteria infect the body, the body’s immune system produces substances to fight these pathogens, which is the antibody we are all familiar with.
Antibodies can bind to pathogens so they can’t infect normal cells in the body.
These antibodies are found in the body’s blood, and are cleaned up by binding to certain proteins of the virus and in conjunction with other functions of the body’s immune system.
At present, many diseases caused by viral infections do not have targeted specific drugs to treat and prevent, most of these diseases are self-limiting, that is, the body through antibody response and other immune response to remove the virus.
But as a result, many people have the same question as Bill Gates, “Why can’t the treated plasma be injected directly into the human body?” ”
Part.2 Serum, plasma, don’t be silly
Now that we mention plasma, let’s simply explain how it differs from serum and blood.
Blood, or whole blood, is a red, sticky liquid that flows between the heart and blood vessels. When blood flows out of our bodies, natural coagulation occurs, and during the clotting process it produces a pale yellow transparent liquid, which is the serum.
When we pull the blood out and treat it with anticoagulants, centrifugation removes the blood cells and gets the red opaque, viscous liquid, the plasma that Bill Gates mentions.
The plasma does contain antibody components, but at the same time it also contains hormones, plasma proteins, lipoproteins and enzymes and other products, the composition is complex. At present, our cognition and function of blood components are not fully studied, so there may be a risk of injecting treated plasma directly into other people’s bodies.
The serum also contains antibody components. In preclinical trials, the transfer of serum from mice containing antibodies to healthy, uninfected mice prevented healthy mice from being infected by the corresponding virus.
Part.3 Serum therapy has long existed, feasibility depends on the actual situation
But, not as Mr. Bill Gates says, serum therapy was actually used by scientists to fight bacterial-induced infections more than 100 years ago.
In 1890, Emil von Behring of Germany (1854-1917) and Kitasato Shibasaburo of Japan, 1853-1931) together announced an important finding: they continue to inject animals with small amounts of non-lethal tetanus bacteria, in the animal’s blood will produce an antitoxin that can be injected into the body of tetanus bacteria toxicity. They also point out that serum can be isolated from animals that have acquired tetanus immunity and injected into other animals to enhance their immunity to tetanus.
This is also what we refer to as “passive protection”, also known as “serotherapy”.
For this infectious disease, this method is theoretically feasible. But as the global population grows, population density is also making the spread of infectious diseases more beneficial. As of the time of writing, the national official notification of the new coronary virus infection has been diagnosed nearly 8000 people, but the cure of fewer than 150 patients.
This may explain the question in everyone’s mind, “Why can’t the treated plasma be injected directly into the human body?” ”
Although serum therapy can be more effective in fighting or preventing diseases caused by viruses or bacteria, the complex composition of serum is uncertain as to whether it will cause other problems. Moreover, its existence time is relatively short, and the number of serum required is relatively large. If we really use 150 people to help 8,000 people treat diseases, or even help the people of the country to fight the virus, I am afraid that they have their blood, it is also difficult to achieve.
Part.4 Healed patients, you are very important.
Although we cannot directly extract the patient’s blood to feed the infected, through modern methods, we can analyze and obtain a whole-human monoclonal antibody sequence that can effectively neutralize the virus by curing the blood of the infected person, to treat and prevent the occurrence of virus-induced diseases.
When patients heal, antigen-specific B cells are produced in their bodies. These cells are present in small amounts in peripheral blood. Through continuous screening, these B cells are captured, and through sequence amplification and analysis, an effective all-human-source monoclonal antibody sequence can be obtained, which can then be prepared in vitro.
Compared with rat-derived monoclonal antibodies, human-mouse chimeric monoclonal antibodies, human-derived monoclonal antibodies, this all-human-derived monoclonal antibody is a good treatment and prevention method.
This antibody has the characteristics of high affinity, high specificity and small toxic side effects, and can overcome the various disadvantages of animal-derived antibodies and chimeric antibodies.
However, although this approach is easy to explain, there are technical difficulties in practice.
First, antigen-specific B cells are very rare in peripheral blood. In one study, the proportion of antigen-specific B cells isolated by researchers in peripheral blood was only 19/500,000.
After separation to B cells, the specific requirements for its sequence amplification and assay sensitivity are also very high. Even if the sequence is amplified to express the antibody, the neutralizing effect of the antibody needs further identification.
Therefore, seemingly simple and effective methods, in practice, the workload and difficulty are enormous.
But with the deepening of research and the continuous development of technology, this method will be more and more, more and more rapidly applied to the prevention and treatment of human diseases. At present, for the coronavirus, the corresponding vaccine and drug research and development is also accelerating.
Finally, I hope you do a good job of protection, keep calm, believe in science, let us together to share the difficulties.