OBJECTIVE: The objective of this review article is to outline the pathology, virology and mechanism of severe acute respiratory syndrome-corona virus-2 (SARS-CoV-2) and to study the regenerative role of mesenchymal stem cells (MSCs) to tackle the lung damage caused by SARS-CoV-2.
BACKGROUND: The MSCs possess trophic potentialities which enable them to find out the sites of injury or inflammation and because of their pleiotropic and pericytic nature, these cells are capable of differentiating into different cell types. The MSCs can be derived from a variety of tissue sources be it adult or embryonic origin. The one major characteristic of MSCs is that they are immunologically naïve in terms of expression of MHC Class II. This very low or no expression of MHC class II makes them useful in clinical settings where they can be used in allogenic transplant cases. This allogenic transplant possibilities of these MSCs makes them one of the most researched stem cells and investigated for cell-based therapies. Though these MSCs are in clinical settings for long the one even more important characteristic which makes them even more in demand is their immunomodulatory properties which have been used in various cases to mitigate the effect of overstimulation of the immune system. In recent times after the pandemic of the novel corona virus disease 2019 (nCOVID-19) generated by SARS-CoV-2, the effect of various MSCs isolated from various tissue sources are being utilized to curb the overstimulation of immune response, so that the immune system can be brought under some regulation to ultimately reduce the effect of inflammation.
METHODS: In this review article, we have reviewed the existing literature, data and ongoing clinical trials by using keywords like novel coronavirus, COVID-19, SARS-CoV-2, MERS-CoV, acute respiratory distress syndrome, mesenchymal stem cells, immunomodulation properties of stem cells, regenerative properties of stem cells, cell therapy, clinical trials of stem cells, clinical trials of COVID-19 and stem cells till 20th August 2020 using database named PubMed, NCBI, Google Scholar, Scopus, Research Gate and Clinicaltrials.gov.
CONCLUSIONS: Thus, concluding the therapeutic potential of MSCs in managing and treating COVID-19.

BACKGROUND: Corona virus disease 2019 (COVID-19) showed a significant difference in case fatality rate between different regions at the early stage of the epidemic. In addition to the well-known factors such as age structure, detection efficiency, and race, there was also a possibility that medical resource shortage caused the increase of the case fatality rate in some regions.
METHODS: Medline, Cochrane Library, Embase, Web of Science, CBM, CNKI, and Wan fang of identified articles were searched through 29 June 2020. Cohort studies and case series with duration information on COVID-19 patients were included. Two independent reviewers extracted the data using a standardized data collection form and assessed the risk of bias. Data were synthesized through description and analysis methods including a meta-analysis.
RESULTS: A total of 109 articles were retrieved. The time interval from onset to the first medical visit of COVID-19 patients in China was 3.38±1.55 days (corresponding intervals in Hubei province, non-Hubei provinces, Wuhan, Hubei provinces without Wuhan were 4.22±1.13, 3.10±1.57, 4.20±0.97, and 4.34±1.72 days, respectively). The time interval from onset to the hospitalization of COVID-19 patients in China was 8.35±6.83 days (same corresponding intervals were 12.94±7.43, 4.17±1.45, 14.86±7.12, and 5.36±1.19 days, respectively), and when it was outside China, this interval was 5.27±1.19 days.
CONCLUSIONS: In the early stage of the COVID-19 epidemic, patients with COVID-19 did not receive timely treatment, resulting in a higher case fatality rate in Hubei province, partly due to the relatively insufficient and unequal medical resources. This research suggested that additional deaths caused by the out-of-control epidemic can be avoided if prevention and control work is carried out at the early stage of the epidemic.
BACKGROUND: CRD42020195606.

OBJECTIVE: Since December 2019, an outbreak of corona virus disease 2019 (COVID-19) occurred in Wuhan, and rapidly spread to almost all parts of China. This was followed by prevention programs recommending Chinese medicine (CM) for the prevention. In order to provide evidence for CM recommendations, we reviewed ancient classics and human studies.
METHODS: Historical records on prevention and treatment of infections in CM classics, clinical evidence of CM on the prevention of severe acute respiratory syndrome (SARS) and H1N1 influenza, and CM prevention programs issued by health authorities in China since the COVID-19 outbreak were retrieved from different databases and websites till 12 February, 2020. Research evidence included data from clinical trials, cohort or other population studies using CM for preventing contagious respiratory virus diseases.
RESULTS: The use of CM to prevent epidemics of infectious diseases was traced back to ancient Chinese practice cited in Huangdi\'s Internal Classic (Huang Di Nei Jing) where preventive effects were recorded. There were 3 studies using CM for prevention of SARS and 4 studies for H1N1 influenza. None of the participants who took CM contracted SARS in the 3 studies. The infection rate of H1N1 influenza in the CM group was significantly lower than the non-CM group (relative risk 0.36, 95% confidence interval 0.24-0.52; n=4). For prevention of COVID-19, 23 provinces in China issued CM programs. The main principles of CM use were to tonify qi to protect from external pathogens, disperse wind and discharge heat, and resolve dampness. The most frequently used herbs included Radix astragali (Huangqi), Radix glycyrrhizae (Gancao), Radix saposhnikoviae (Fangfeng), Rhizoma Atractylodis Macrocephalae (Baizhu), Lonicerae Japonicae Flos (Jinyinhua), and Fructus forsythia (Lianqiao).
CONCLUSIONS: Based on historical records and human evidence of SARS and H1N1 influenza prevention, Chinese herbal formula could be an alternative approach for prevention of COVID-19 in high-risk population. Prospective, rigorous population studies are warranted to confirm the potential preventive effect of CM.