On the evening of February 13, Zhang Dingyu, the director of Wuhan Jinyintan Hospital, said at a press conference on the prevention and control of pneumonia of a new type of coronavirus infection in Hubei Province that the hospital is currently conducting initial plasma treatment for patients during rehabilitation.

Recovery plasma therapy is a method of collecting antibody-rich blood from patients who have recovered and transfusion to other patients after treatment.

In the absence of vaccines and effective drugs, plasma therapy in the recovery period was highly anticipated.

On February 5th, the National Health and Health Committee issued the “Diagnosis and Treatment of Pneumonia of New Coronavirus Infection (Trial Fifth Edition)”, which states that “recovery plasma treatment can be used.”

On February 7, Wang Guiqiang, chairman of the Infectious Diseases Branch of the Chinese Medical Association and director of the Department of Infectious Diseases of the First Hospital of Peking University, introduced at a press conference, “In the treatment of critically ill patients, in addition to antiviral therapy, traditional Chinese medicine and traditional Chinese medicine, some The application of new diagnosis and treatment technology will further reduce the fatality rate of critically ill patients. At present, the treatment of recovery plasma has been used in Shenzhen Third Hospital and has achieved good results. “

On the evening of February 13, the official Weibo of the SASAC reported that China Biological Corporation had completed the collection of plasma from some recoverers and carried out the preparation of New Coronavirus-free plasma products and special immunoglobulins. After rigorous blood biosafety testing, virus inactivation, and antiviral activity testing, special immune plasma has been successfully prepared for clinical treatment. In the first phase, the New Crown Special Free Plasma Treatment of 3 critically ill patients was carried out in the First People’s Hospital of Jiangxia District. Currently, more than 10 critically ill patients are treated with the follow-up hospital. Clinically, 12 to 24 hours after receiving the treatment, the main inflammation indicators in the laboratory decreased significantly. The proportion of lymphocytes increased, key indicators such as blood oxygen saturation and viral load improved, and clinical signs and symptoms improved significantly.

According to Chinese biology, from the perspective of clinical pathology, most patients with new crown pneumonia after treatment and rehabilitation will produce specific antibodies against the new crown virus in the body, which can kill and clear the virus. At present, under the premise of lack of vaccines and specific therapeutic drugs, the use of this special-free plasma product to treat neocoronavirus infection is the most effective method, which can significantly reduce the mortality of critically ill patients.

The relevant person in charge of China Biological Research and Development also said that the collection, preparation and serial testing of New Coronavirus-free plasma has good safety, mature preparation technology and short time required. At present, the “2019-nCoV infection recovery period patient-specific plasma and specific immunoglobulin preparation” project undertaken by China Biological has been awarded the national key R & D plan “public safety risk prevention and control and emergency technology equipment” key project organized by the Ministry of Science and Technology. Project establishment.

The key is the “antibody”. “Antibodies are one of the body’s most important weapons against viral infections. Once neutralizing antibodies against the virus are produced, they are not only large in quantity and long-lasting, thereby highly effectively blocking the virus from entering the cell, and the virus cannot enter the cell and cannot reproduce. , Amplification, the extracellular virus will gradually decompose itself, and this is the magic of antibodies. “Huang Bo, professor of the Department of Immunology, Peking Union Medical College, Chinese Academy of Medical Sciences, and vice chairman of the Chinese Institute of Immunology, said that antibodies work. The pathways are divided into two categories: neutral surface antibodies bind to the virus to prevent the virus from entering the cell, which can be understood as “defending the enemy from outside the country”; non-neutral surface antibodies bind to the virus to mediate the immune cell phagocytosis and eliminate the virus. It is “kill the enemy within the country.”

Antibody therapy also has potential risks. “For neocoronary pneumonia, too many hopes are pinned on antibodies, but antibodies are not as simple as generally understood. It does not mean that the body can clear the virus as long as it has antibodies. For the complexity of antibodies, and even the worsening side of the disease, we need Have enough knowledge. “Huang Bo emphasized.

Neutralizing surface antibodies play a protective role primarily by preventing the virus from entering lung epithelial cells. Non-neutralizing surface antibodies can mediate virus entry into macrophages.

Huang Bo said that in the early stage of virus infection, the macrophages will phagocytose the antibody-mediated virus and then deliver it to the site of intracellular degradation to degrade the virus, thereby exerting an antiviral effect. However, in the middle and late stages of virus infection, macrophages cannot degrade the engulfed virus because of various inflammatory stimuli. Instead, the virus escaped by some means and survived inside the macrophages. “In this way, the viruses that live in macrophages will synthesize new virus particles on the one hand and promote infection; on the other hand, they will stimulate macrophages to release too many pro-inflammatory factors, which will also cause immune damage to the lungs.” ” In particular, the virus may promote inflammatory storms through macrophages. “Huang Bo emphasized that damage to lung cells by new coronaviruses generally does not directly lead to death of patients, and the main cause of patient death is non-specific immune cells. Excessive activation, release a large number of pro-inflammatory factors, such as interleukin-1, interleukin-6, tumor necrosis factor, etc., forming the so-called cytokine storm, scientific name is cytokine release syndrome, pathological damage is mainly manifested in Capillary damage and increased permeability. “Promoting inflammatory storms could be a potential risk for antibody therapy.”

Huang Bo also introduced that the nucleic acid substance RNA of the new coronavirus is located at the core and is enveloped by a nucleocapsid protein. The outer layer is an envelope with a variety of proteins on the envelope. These viral proteins are foreign proteins. “That is to say, for any kind of foreign protein, the body may produce antibodies specifically directed against it. Therefore, individuals infected with the new coronavirus can produce a variety of different antibodies against the virus in the body. But most antibodies are actually There is no antiviral effect, and only antibodies that recognize the proteins on the surface of the viral particles can have an antiviral effect. “

“Of course, if the inactivated virus particles are directly injected into the body, it will cause the body to produce antibodies against the virus. This is a traditional vaccine that produces the effect of vaccination. The current development of vaccines for new crown virus also follows this basic principle.” Huang Bo also pointed out that the current progress in plasma treatment during the recovery period has important guiding significance for vaccine development, because the purpose of vaccination is to make the body produce antibodies, in fact, to produce neutralizing antibodies against the surface proteins of the virus particles. It is easy to vaccinate the body to produce antibodies, but it is not easy to produce such protective neutralizing antibodies, which poses a huge challenge to vaccine development. We should take a cautious attitude and carry out in-depth and detailed work.