Journal of Pathobiology Reaearch
Volume:23 Issue: 1, 2020

Coronavirus disease 2019 (COVID-19) is a virally-induced pneumonia caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This is the third disease-causing coronavirus after severe acute respiratory syndrome coronavirus (SARS-CoV) and the middle east respiratory syndrome coronavirus (MERS-CoV) which has been known in the human population in the 21st century. To this date (20th of Mehr, 1399), more than thirty-four million people have been infected by this virus and more than a million have lost their lives because of it which further signifies the importance of COVID-19 prevention and treatment. In this review article, we first take a look at the history of the famous coronaviruses and then introduce the genetic and pathophysiology of SARS-CoV-2 in a detailed manner. After discussing the related clinical manifestations, we shed a light on the treatments that have been assessed to this date. In the end, we will briefly discuss the vaccines that are currency being developed and highlight their success rate, so far. It is delightful to assert that out own research team is currently developing an oral and/or respiratory vaccine against SARS-CoV-2 which is composed of spike-surface decorated chitosan nanoparticles.

Covid-19 is a highly infectious viral disease caused by SARS-CoV-2, which has spread worldwide since its emersion in December 2019, causing an unprecedented pandemic. Currently, it has no targeted vaccines or treatments, and effective treatment options are very limited. It is important to identify drugs that effectively inhibit a specific target of the SARS coronavirus. This is the third deadly outbreak of coronaviruses in human society which has put pressure on the global health care system and affected the global economy a well. However, the treatment options of Covid-19 are still very limited. The development of drugs that target and inhibit essential proteins in the viral life cycle is a practical approach to overcoming this hard situation. The main protease, a cysteine protease, is an attractive target for antiviral drugs against SARS-CoV-2 and other coronavirus infections due to its essential role in viral replication and transcription. To quickly detect effective compounds for clinical use, programs such as molecular docking drug design and virtual screening of pre-designed drugs to identify new compounds and drugs that target the main protease of the COVID-19 are performed. Combining these structural studies, virtual screening, and experimental screen, several therapeutic candidates such as repurposed drugs and ab initio designed drugs have been proposed. In this review study, suggestions for inhibitors and possible potentially effective drugs against the main protease of SARS-CoV-2 were discussed. This study paves the way for advanced experimental research to evaluate the pharmacological potential of these compounds for the treatment of Covid-19.

The Coronaviridae family includes viruses that are considered the causative agents of respiratory infections, and among human RNA viruses have the largest genome. Coronaviruses undergo elusive genetic changes through mutation during replication. A gene mutation is a permanent alteration in the nucleic acid sequence; if it occurs in large numbers, it causes changes in the biological features of a species. Fundamentally, viruses adapt to the human body during replication. Several studies have shown that most mutations do not have much effect on pathogenicity. Sequence diversity in new coronaviruses is very low. However, antigen drift has been observed among some coronaviruses. Most coronavirus mutations occur intermittently in Iran and other countries and have little effect on the pathogenicity of the virus but have increased its rate of transmission. In mutated viruses, deletion of nucleotide sequences has been observed relatively in some reading frames extensively. Studies have shown that the host protein induced mutagenesis through interaction via viral proteins. The most important mutation in SARS-CoV2 compared to the original Wuhan virus was the spike D614G mutation and the lineage of B.1.1.7, 20I/501Y.V1become the dominant and exhibit greater virus spread but did not associate with higher viral loads and morbidity. However, it may affect the effectiveness of the vaccines and mortality rate.

The new coronavirus was firstly identified in the late December 2019 that causes severe respiratory and other organ complications in Covid-19 patients. Although many attempts have been employed to introduce and provide effective medications against this infection, there is still no definitive treatment for the infection. However some agents have shown promising effects in patients and some others are in preliminary or clinical studies. Monoclonal antibodies are of great interest in the treatment of Covid-19, but despite the fact that more than 120 clinical trials have been performed or are being completed; only tocilizumab has shown promising results and is sometimes used in therapeutic protocols. In this review, therapeutic monoclonal antibodies against Covid-19 that are currently in phase 3 or higher clinical trial have been discussed.

The new Coronavirus, which was named SARS-CoV-2 is one of the members of the Coronavirus family, which induces Covid-19 or acute respiratory infection. This virus was firstly known in 2019 in Wuhan, China; and then, rapidly propagated around the world. In this review, we will present the structure and function of the Spike (S) protein in this virus and its receptors on the host cells. In addition to ACE2, which was initially identified as the cell surface receptor of this virus, it was observed that CD147 and GRP 78 also act as the receptors on host cells. Also, based on the mechanism of action, a brief introduction will present the drugs used to treat this Coronavirus. The drugs that target S protein, Proteinases; RNA-dependent RNA polymerases, helicases, or structural lipids of the virus membrane. In addition, the proposed natural products which are currently recommended as supplements are discussed. For example, flavonoids, polyphenols, and polar compounds are substances whose antiviral effects against Coronavirus have been studied and demonstrated. In conclusion, since the effective drug to eradicate this virus is not yet known, it seems that according to the structural characteristics and mechanism of action, using natural compounds as a complementary or preventive medicine will be useful to inhibit or delay the entrance, proliferation, and/ or infectivity of the virus.

In late 2019, a new coronavirus called SARS-COV-2 triggered an epidemic in Wuhan, China, and now exists worldwide. SARS-COV2 is a highly contagious virus and is the cause of the current COVID19 pandemic. Covid19 can affect anyone, from mild to very severe. For some other illnesses caused by respiratory viruses (such as the flu), some people may become more severely ill because of characteristics such as old age or certain medical conditions that increase the risk of the disease. The purpose of this review study is to monitor the disease, field research, and factors that may contribute to the severity of the pathogen so that we can better understand why some people may have severe COVID19, which is one of the most important priorities. The CDC's strategy is to combat COVID19, which can provide critical information in decisions to protect the most vulnerable population. The review study was collected from articles indexed in Latin databases and reports from reputable health organizations from January to July 2020.

Since the emergence of the novel SARS-CoV-2 coronavirus in December 2019, various drugs have been proposed as antiviral agents for treating the coronavirus disease-2019 (COVID-19) patients. Among the very first drugs to be utilized in the clinic were the aminoquinolines chloroquine and hydroxychloroquine (HCQ). At the time this work started, the US FDA and EU EMA had given emergency approval for the use of chloroquine and HCQ in COVID-19 patients. Chloroquine and HCQ have been commonly used for treating malaria and various autoimmune diseases. Additionally, both drugs have been shown to exert other therapeutic effects, including antiviral effects against SARS and MERS causing viruses.  The exact antiviral mode of action of Chloroquine and HCQ is unclear even though these drugs exert a broad range of antiviral effects. HCQ is classically considered as an inhibitor of endocytic pathways through  elevation of endosomal pH, its detailed molecular mechanisms of action as an antiviral compound remains elusive In-vitro studies show that both drugs can block the viral replication of SARS-CoV- 2 in cell cultures, but a high-level assessment suggested that calculated extracellular lung concentrations are well below the in vitro efficacy values and therefore the drug has low potential for in vivo activity at standard dosing regimens.

SARS-COV-2, the latest member of Coronaviridea family as the cause of the recent global epidemic, has inflicted sever damages in different fields on most governments. Appropriate strategies such as identifying infected individuals and isolating them, trying to produce an effective vaccine, finding efficient treatment and making correct decisions in the social, economic and health fields are the current priorities of the world. Serological tests provide useful information in all of the above areas. In this article we will discuss the importance of performing SARS-COV-2 serological tests in diagnosis, vaccination, treatment and proper planning in the society.