ABSTRACT
Studies suggest that there is a complex interaction between parasitic infections, human microbiota, and host immunity. Reports have shown that there is the prevalence of viral diseases have inverse correlations with their severities (as is the case for Covid-19), their resulting mortalities, and helminth infections in endemic areas. This review study was conducted to discover the possible association between parasitic infections and Covid-19 epidemics from immunological, pathological, and therapeutic aspects. Our studies were conducted by reviewing texts, reports, and articles on reputable websites such as PubMed, Science Direct, medRxvi, Google Scholar, and bioRxiv published by 2022 07 April for keywords such as a parasite, helminth, radioactive, COVID-19 or SARS-CoV-2. In particular, reports of co-infection with helminths with complications and severity of Covid-19 in endemic areas were considered. The findings indicate that parasitic helminths can regulate host immune responses associated with a viral infection. For example, intestinal parasitic infections may be effective in reducing the symptoms of SARS-CoV-2 and the complications of Covid-19. Infected hosts can induce an innate and Th2-compatible immune response to CD4+ T cells, eosinophils, and interleukins (IL-4, IL-5, and IL-10). Chronic helminth infections prevent strong immune responses by altering the host response to T helper 2 (Th2). Interestingly, some antimalarial drugs, such as Artemisinin-based combination therapies (ACTs), may inhibit SARS-CoV-2-induced severe acute respiratory syndrome (SARS). Parasitic infections may alter the host's immune response to SARS-CoV-2 with potentially beneficial or detrimental effects. However, more large-scale epidemiological studies are needed to uncover the links between parasitic infections and COVID-19 and to clarify existing ambiguities.
ABSTRACT
Due to lack of effective treatment for novel pandemic coronavirus disease (COVID-19) caused by severe acute respiratory syndrome corona-virus-2 (SARS-CoV-2), the prevention strategies are the best choices to significantly control increasing number of patients. Numerous studies suggest an association between vitamin D and C and the outcomes of SARS-CoV-2 infection. Therefore, supplementation of vitamins such as D and C has been recommended prevention and treatment of the COVID-19. Vitamin D as an immunomodulator hormone could affect various respiratory infections by maintaining the immune system and blocking hyper-inflammatory responses like cytokine storm through decreasing viral replication and regulating the levels of proinflammatory/anti-inflammatory cytokines. There are also some evidences that vitamin D could alter severity of COVID-19. The effectiveness of vitamin C in the prevention and treatment of coronavirus has also been undertaken by several studies. Due to the important role of vitamin C in the immune system, a deficiency of this vitamin may increase the incidence, severity and the risk of death of COVID-19 disease. This could explain by this fact that vitamin C deficiency increases the risk of infections, decreases the immune system response and increases the risk of pneumonia. People with chronic diseases as high-risk COVID-19 patients also showed deficiency of these vitamins which could explain the severity and the high rate of mortality among them. Thus, it seems that sufficient vitamin D and C level in serum may have positive impact on decreasing risk of COVID-19 infection. Considering all aspects, we try to overviewed on the potential role of supplementation of vitamin D and C in COVID-19 disease. We summarized suggested impacts of these vitamins on SARS-CoV-2 and its pathogenesis. We also discussed mechanisms in which these two vitamins involved that could alter the COVID-19 infection.