SARS-CoV-2: Current trends in emerging variants, pathogenesis, immune responses, potential therapeutic, and vaccine development strategies.

More than a year after the SARS-CoV-2 pandemic, the Coronavirus disease 19 (COVID-19) is still a major global challenge for scientists to understand the different dimensions of infection and find ways to prevent, treat, and develop a vaccine. On January 30, 2020, the world health organization (WHO) officially announced this new virus as an international health emergency. While many biological and mechanisms of pathogenicity of this virus are still unclear, it seems that cytokine storm resulting from an immune response against the virus is considered the main culprit of the severity of the disease. Despite many global efforts to control the SARS-CoV-2, several problems and challenges have been posed in controlling the COVID-19 infection. These problems include the various mutations, the emergence of variants with high transmissibility, the short period of immunity against the virus, the possibility of reinfection in people improved, lack of specific drugs, and problems in the development of highly sensitive and specific vaccines. In this review, we summarized the results of the current trend and the latest research studies on the characteristics of the structure and genome of the SARS-CoV- 2, new mutations and variants of SARS-CoV-2, pathogenicity, immune response, virus diagnostic tests, potential treatment, and vaccine candidate.

Is there any potential management against COVID-19? A systematic review and meta-analysis.

PURPOSE: A recent survey has shown that the COVID-19 pandemic has culminated in dramatical and critical treatment particularly in acute infected patients. In fact, this systematic review-meta-analysis was directly pertained to estimation at the efficient value of some clinical managements to confront the COVID-19 infection. METHODS: Pubmed, Embase, Scopus, Cochrane, and Scholar databases were searched from inception to July 1, 2020, to identify studies reporting the current treatment process and medications (e.g. hydroxychloroquine, antiviral therapy, convalescent plasma, and immunomodulatory agents) for COVID-19. A random-effects model meta-analysis was performed to calculate the relative risk (RR) with 95% confidence intervals (CI). The outcomes of this study were the frequency of negative conversion cases, clinical improvements, mechanical ventilation demand, intensive care unit (ICU) entry, and mortality. The standard treatment refers to the published guidelines and specialist experience which varies in different articles, and the proposed treatment refers to the kind of interest suggested in the included studies. RESULTS: A number of 45 articles met the eligibility criteria (out of 6793 articles). Among them, 26 articles involving 3263 patients were included in quantitative analysis. Anti-COVID-19 interventions could significantly increase clinical improvement (RR 1.17, 95% CI 1.08-1.27; I2 = 49.8%) and reduce the mortality rate (RR 0.58, 95% CI 0.35-0.95; I2 = 74.8%). Although in terms of negative conversion, ICU entry, and mechanical ventilation demand, clinical intervention had no beneficial effect. The clinical effect of immunomodulatory agents (especially tocilizumab and anakinra) was noticeable compared to other medications with RR of 0.22 (95% CI 0.09-0.53; I2 = 40.9%) for mortality and 1.25 (95% CI 1.07-1.46; I2 = 45.4%) for clinical improvement. Moreover, Antivirals (RR 1.13, 95% CI 1.01-1.26; I2 = 47.0%) and convalescent plasma therapy (RR 1.41, 95% CI 1.01-1.98; I2 = 66.6%) had significant beneficial effects on clinical improvement. CONCLUSION: Based on our findings, all the included interventions significantly declined the mortality and enhanced clinical improvements with no effect on negative conversion and mechanical ventilation demand. Especially, immunomodulators and plasma therapy showed favorable outcomes. An evaluation on the efficacy of proposed treatment against COVID-19.