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25

2020

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02

Scientific Research News | Research Progress of novel coronavirus Pneumonia (COVID-19) (XXV)


1. COVID-19 Alert

■ According to Korean media reports, as of the afternoon of February 2, local time, there were 23 new confirmed cases of new coronary pneumonia in South Korea, and the total number of confirmed cases increased to 46. In addition, 602 of the confirmed cases of new coronary pneumonia in South Korea have died. Earlier in the day, South Korean President Moon Jae-in announced that the warning level for the new crown pneumonia epidemic would be raised to the highest level. This is the second time in 5 years that the South Korean government has issued the highest level of infectious disease warning after the 2009 H1N1 influenza.

■ On February 2, Chen Kaixian, academician of the Chinese Academy of Sciences and researcher of the Shanghai Institute of Materia Medica, Chinese Academy of Sciences, was interviewed by a reporter from Jiefang Daily. Regarding the question of why traditional Chinese medicine has obvious clinical effects in this epidemic, Academician Chen Kaixian said: The new crown pneumonia is a new disease, caused by the new coronavirus, showing a series of new characteristics in pathology, etiology and epidemiology, which has brought great challenges to the diagnosis and treatment of doctors and researchers. We do not have a specific drug for new crown pneumonia, the development of specific drugs takes a relatively long time, patients are currently receiving mainly supportive, symptomatic therapy, doctors also use some antiviral and anti-infection drugs according to the situation.

In the face of this outbreak, traditional Chinese medicine has proven to play an important role. In Chinese medicine theory, new crown pneumonia belongs to the temperature disease epidemic, which is a general term for a type of external acute fever caused by feeling "external evil". For thousands of years, Chinese medicine experts have put forward many theories about temperature disease, accumulated rich clinical practice experience, and the prescriptions and over-the-counter drugs used have two effects: one is the systemic conditioning effect, enhance the patient's resistance to the disease, alleviate the damage to organ function, and allow the patient to recover health quickly. Second, some traditional Chinese medicines for the treatment of warm diseases contain heat-clearing and detoxification ingredients, which themselves also have a certain inhibitory effect on the virus. Of course, this aspect remains to be studied in depth.

From the clinical practice of this epidemic, the medical community across the country has widely adopted the method of integrating traditional Chinese and Western medicine, and achieved good clinical results. In Shanghai, the prevalence rate of traditional Chinese medicine treatment in the municipal public health clinical center exceeds 90%, which makes the cure and discharge time of patients advance by about 2-3 days on average. In Wuhan, some hospitals also use pure traditional Chinese medicine treatment, and the results are also very good, so far not a single patient has died. For this reason, the central government requires continuous optimization of diagnosis and treatment plans, and adheres to the principle of integrating Chinese and Western medicine and attaching equal importance to Chinese and Western medicine. In the newly released "New Coronary Pneumonia Diagnosis and Treatment Plan (Trial Sixth Edition)", the content of traditional Chinese medicine accounts for a considerable proportion.

■ On February 2, at the 22th press conference on the prevention and control of the new coronavirus pneumonia epidemic in Zhejiang Province, Song Zhiheng, deputy director of the Department of Science and Technology of Zhejiang Province, announced that the first batch of vaccines has produced antibodies and entered the stage of animal experiments, recombinant adenovirus vector vaccines, began to carry out recombinant virus culture, and animal experiments will be carried out in the near future. It is reported that Zhejiang Province's screening of the new crown virus has reached the fourth generation, and researchers are currently racing against time to overcome problems. However, Song Zhiheng also reminded that we must clearly realize that the cycle of vaccine research and development is relatively long, and we must respect scientific laws and go through a scientific, rigorous and safe research process.

■ On February 2, WHO Director-General Tedros Adhanom Ghebreyesus said via video link at an emergency meeting at the African Union headquarters that WHO would work with African countries to prepare for possible outbreaks to prevent the spread of the new coronavirus in countries with weak health systems. Tedros said that WHO has appointed two special envoys to provide strategic advice on the prevention and control of the new crown pneumonia epidemic in Africa; Thirteen priority prevention and control countries have also been identified in Africa based on exchanges with Chinese personnel. In terms of funding, WHO has launched the Strategic Preparedness and Response Plan, which calls for US$22 million to focus on supporting countries at higher risk of COVID-2 prevention and control. He also said that more and more African countries have been able to use laboratory test kits provided by WHO for new coronavirus testing; Tens of thousands of pieces of personal protective equipment are being shipped in batches across Africa; Over the past month, about 13,6 African health workers have been trained in WHO's online course on the coronavirus outbreak. Tedros said the "window of opportunity" to curb the spread of the new coronavirus is narrowing and countries should prepare for the response as soon as possible to prevent the spread of the epidemic. "I pledge that WHO, together with all African countries, will do everything we can to prevent the spread of the virus and to detect and treat cases of infection as early as possible."

■ On February 2, the research group of Qi Jianxun, a researcher at the Institute of Microbiology, Chinese Academy of Sciences, analyzed the 20.2 angstrom resolution crystal structure of the new coronavirus's S protein RBD and human cell receptor ACE2 protein complex, revealing how the S protein and the receptor ACE5 work with each other at the atomic level. At the same time, the researchers uploaded the data to the National Microbial Science Data Center (number: NMDCS2) as soon as possible, and shared the research results with scientists around the world, hoping to jointly tackle the virus epidemic as soon as possible.

2. Advances in biological research on COVID-19

■ The team of Jorerg Jores and Volker Thiel of the University of Bern in Switzerland proposed a virus construction strategy based on reverse genetics on the bioRxiv bioRxiv website: instead of extracting intact viruses from patient samples, yeast can be used to produce active new coronaviruses, or viral tools for experiments can be modified on demand. It should be noted that this is a basic research work for viral reconstruction based on known viral genomes, which is not the same thing as rumors that "the new coronavirus is synthetic". The researchers first constructed antisense DNA sequences based on viral nucleic acid RNA sequences. Due to the large length of the entire sequence, it cannot stably replicate in tool bacteria, so the researchers adopted a mature and ingenious method: transformation conjugation recombination technology. The researchers disassembled the antisense DNA into 12 DNA fragments 0.5-3.4 kbp long with overlapping end sequences, and introduced GFP (green fluorescent protein sequence), using the homologous recombination system in Saccharomyces cerevisiae to reconstitute a complete gene sequence in yeast. Later, in vitro, the antisense DNA is transcribed into infectious viral RNA with T7 RNA polymerase. After RNA was introduced by electroporation, normal VeroE6 cells were found to be infected and fluorescent. The 2019-nCoV total synthesis technology proposed in this study can produce or modify a large number of live viruses within a week for use in medical and research institutions to break through the limitation of virus sources. In the future, the new coronavirus may undergo many mutations, and synthetic synthesis will be an important means to understand and predict the development trend of virus characteristics [1].

3. Epidemiological studies of COVID-19

The team of Vittoria Colizza, director of research at the French Institute of Health and Medicine, published a study entitled "Preparedness and vulnerability of African countries against importations of COVID-19: a modelling study" in The Lancet. The risk of virus introduction into Africa and the capacity of African countries to detect and treat the virus were assessed. The results show that Egypt, Algeria and the Republic of South Africa are the African countries most likely to spread the virus due to their high level of trade with China. On the other hand, these countries have the highest SPAR (Annual Report of States Parties on Self-Assessment) and IDVI (Infectious Disease Vulnerability Index) on the continent and can effectively detect and contain the spread of the virus (SPAR means that each country must report its resources to the World Health Organization every year to respond to the outbreak, it consists of 24 items with a total score between 0 and 100 points, 100 indicates strong preparedness for the epidemic, and vice versa; The IDVI score is credited as a maximum of 100 points, where 0 corresponds to extreme vulnerability and 100 corresponds to minimum vulnerability). Other countries, such as Nigeria, Ethiopia, Sudan, Angola, Tanzania, Ghana and Kenya, have a low risk of importation, but low SPAR and IDVI scores, raising concerns that possible imported cases could spread locally or even nationally because they could not be detected. The findings of this study will help inform increased preparedness and response to outbreaks in selected African countries found to be at moderate to high risk of importing COVID-19 and relatively low capacity to manage health emergencies [2].

■ AT THE LANCET RESPIRATORY MEDICINE ON FEBRUARY 2, THE TEAM FROM TONGJI MEDICAL COLLEGE OF HUAZHONG UNIVERSITY OF SCIENCE AND TECHNOLOGY AND WUHAN JINYINTAN HOSPITAL JOINTLY ISSUED A PAPER SUMMARIZING THE SITUATION OF 22 CRITICALLY ILL PATIENTS ADMITTED TO JINYINTAN HOSPITAL IN THE EARLY STAGE OF THE EPIDEMIC. Data show that as of February 52, 2 of these 9 patients have died, and the case fatality rate in the 52 days after admission to the ICU still reaches 32.28%, and many patients have suffered damage to the heart, liver, kidney and other organs. The admission time of 61 patients in Jinyintan Hospital was from December 5 last year to January 52 this year, accounting for about 12% (24/1) of the new crown pneumonia patients in the hospital during the same period, and the patients were all local residents of Wuhan. Of these patients, 26 had visited the Huanan Seafood Market, and another 7 had been exposed to other confirmed or highly suspected COVID patients. From the overall characteristics, patients are still mainly middle-aged and elderly, men account for two-thirds, and patients with underlying diseases such as cardiovascular disease and diabetes account for about 51%. The median time from the earliest onset of symptoms to confirmation of double pneumonia by imaging is 710 days, and the median time to ICU admission is 17 days. By the time of ICU transfer, most patients already showed signs of organ damage, two-thirds had acute respiratory distress syndrome (ARDS), and 10, 5, and 9 patients had acute kidney injury, liver dysfunction, and myocardial injury, respectively. In conclusion, the mortality rate of severely ill patients with 15-nCoV pneumonia is high. Nonsurvivors may survive within 15 to 12 weeks of ICU admission. Older patients (> 2019 years) with underlying medical conditions and ARDS are at increased risk of death [1].

4. Novel coronavirus information base

■ The research team from the China Bioinformatics Center and other units published an article entitled "2019 Novel Coronavirus Information Database" in the journal "Genetics": In order to promote the application of 2019-nCoV data sharing and timely provide virus-related information to the global public, the National Bioinformatics Center (CNCB)/National Genomic Science Data Center (NGDC) established the 2019 Novel Coronavirus Information Database (2019nCoVR, https:// bigd.big.ac.cn/ncov)。 The library integrates 2019-nCoV nucleotide and protein sequence data, meta information, academic literature, news trends, popular science articles and other information publicly released by the German Global Influenza Virus Database, the US National Biotechnology Information Center, Shenzhen (national) gene bank, the National Microbial Science Data Center and CNCB/NGDC and other institutions, and carries out genome sequence variation analysis and provides visual display of different coronavirus strains. At the same time, 2019nCoVR seamlessly connects to the relevant databases of CNCB/NGDC, providing data services such as the original genome sequencing data of new sequenced virus strains, online convergence, management and sharing of assembled sequences, and synchronous release of international databases. This paper comprehensively elaborates on the data collection, management, release and use of 2019nCoVR, so as to facilitate users to understand the functions and data status of the library, and provides an important basis for accelerating the research on virus classification and tracing, mutation evolution, rapid detection, drug research and development, and precise prevention and treatment of novel pneumonia [4].

Bibliography:

[1] Thao TTN, Labroussaa F, Ebert N, et al. Rapid reconstruction of SARS-CoV-2 using a synthetic genomics platform. bioRxiv 2020:2020.02.21.959817.

[2] Gilbert M, Pullano G, Pinotti F, et al. Preparedness and vulnerability of African countries against importations of COVID-19: a modelling study. The Lancet.
[3] Yang X, Yu Y, Xu J, Shu H, et al. Clinical course and outcomes of critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a single-centered, retrospective, observational study. Lancet Respir Med 2020.
[4] Zhao Wenming, Song Shuhui, Chen Meili, et al 2019 novel coronavirus Information Base [J] Genetics

 

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