The potential importance of autophagy genes expression profile dysregulation and ATG polymorphisms in COVID-19 pathogenesis.

Autophagy is one of the important mechanisms in cell maintenance, which is considered associated with different pathological conditions such as viral infections. In this current study, the expression level and polymorphisms in some of the most important genes in the autophagy flux in COVID-19 patients were evaluated. This cross-sectional study was conducted among 50 confirmed COVID-19 patients and 20 healthy controls. The COVID-19 patients were divided into a severe group and a mild group according to their clinical features. The expression levels of ATG5, ATG16L1, LC3, and BECN1 were evaluated by the 2-∆∆CT method and beta-actin as the internal control. The polymorphisms of the ATG5 (rs506027, rs510432) and ATG16L1 (rs2241880 or T300A) were evaluated by the Sanger sequencing following the conventional PCR. The mean age of the included patients was 58.3 ± 17.9 and 22 (44%) were female. The expression levels of the LC3 were downregulated, while BECN1 and ATG16L1 genes represent an upregulation in COVID-19 patients. The polymorphism analysis revealed the ATG16L1 rs2241880 and AGT5 rs506027 polymorphism frequencies are statistically significantly different between COVID-19 and Healthy controls. The autophagy alteration represents an association with COVID-19 pathogenesis and severity. The current study is consistent with the alteration of autophagy elements in COVID-19 patients by mRNA expression-level evaluation. Furthermore, ATG16L1 rs2241880 and AGT5 rs506027 polymorphisms seem to be important in COVID-19 and are highly suggested for further investigations.

Review on Approved and Inprogress COVID-19 Vaccines.

The last generation of Coronavirus named COVID-19 is responsible for the recent worldwide outbreak. Concerning the widespread and quick predominance, there is a critical requirement for designing appropriate vaccines to surmount this grave problem. Correspondingly, in this revision, COVID-19 vaccines (which are being developed until March 29th, 2021) are classified into specific and non-specific categories. Specific vaccines comprise genetic-based vaccines (mRNA, DNA), vector-based, protein/recombinant protein vaccines, inactivated viruses, live-attenuated vaccines, and novel strategies including microneedle arrays (MNAs), and nanoparticles vaccines. Moreover, specific vaccines such as BCG, MRR, and a few other vaccines are considered Non-specific. What is more, according to the significance of Bioinformatic sciences in the cutting-edge vaccine design and rapid outbreak of COVID-19, herein, Bioinformatic principles including reverse vaccinology, epitopes prediction/selection and, their further applications in the design of vaccines are discussed. Last but not least, safety, challenges, advantages, and future prospects of COVID-19 vaccines are highlighted.

Idiopathic thrombocytopenic purpura as a hematologic manifestation of COVID-19 infection: A case report.

The hematologic system is one of the vulnerable parts of the human body in coronavirus disease-2019 (COVID-19) infection. Lymphopenia and disseminated intravascular coagulation (DIC) are among the most frequent consequences of COVID-19. Idiopathic thrombocytopenic purpura is one of the common causes of thrombocytopenia in adults. It is defined by thrombocytopenia when platelet counts <105/µl in the absence of anemia and leukopenia. Traditionally, infections, typically viral, have been known as the main culprits of low platelet counts before the involvement of ITP. According to the literature, C virus (HCV), HIV, varicella-zoster virus (VZV), and cytomegalovirus (CMV) are considered secondary causative agents for the development of ITP. In this study, we reported a case that was afflicted with concurrent severe thrombocytopenia diagnosed as ITP and COVID-19 infection.

The role of lovastatin in the attenuation of COVID-19.

The mounting evidence regarding the pathogenesis of COVID-19 indicated that the cytokine storm has an axial role in the severity of this disease, which may lead to thrombotic complications, acute respiratory distress syndrome (ARDS), and myocardial damage, among other consequences. It has recently been demonstrated that statins are known to have anti-viral, anti-inflammatory, anti-thrombotic, and immunomodulatory features; however, their advantage has not been evaluated in COVID-19. This study aimed to investigate the protective effects of lovastatin in intensive care unit (ICU) patients with COVID-19. The case-control study consists of 284 ICU patients, which classified into three groups as follows: 1) the patients who no received lovastatin as a control (92 patients), 2) patients received 20 mg per day lovastatin (99 patients), and 3) patients received 40 mg per day lovastatin (93 patients). Each group's demographic and clinical parameters, along with CRP, interleukin (IL)-6, IL-8 levels, and mortality rate, were studied in three-time points. The results showed that there was no statistically significant difference between our study groups in terms of age and sex. (P > 0.05). Besides, in patients, receiving lovastatin the CRP, IL-6, IL-8 levels were significantly decreased from T1 to T3 than to the control group. Our results also showed that the use of lovastatin in COVID-19 patients significantly reduced the length of hospitalization in the ICU compared with the control group. In addition, our results showed that the mortality rate in patients receiving lovastatin was lower when compared to the control group; however, this difference was not statistically significant. Since the cytokine storm is a significant factor in the pathology of SARS-CoV-2, our findings highlighted the potential use of lovastatin to mitigate the inflammatory response induced by SARS-CoV-2 infection.

A possible pathogenic correlation between neutrophil elastase (NE) enzyme and inflammation in the pathogenesis of coronavirus disease 2019 (COVID-19).

A growing body of evidence indicates that neutrophil elastase (NE) is involved in the pathogenesis of respiratory infectious diseases, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to analyze the dynamic changes in serum levels of NE associated with inflammation, disease activity, and mortality rate in patients with COVID-19. We measured the serum concentrations of NE, C-Reactive protein (CRP), interleukin (IL)- 4, IL-6, IL-8, IL-10, and vitamin D levels in 83 ICU and 69 non-ICU patients compared with 82 healthy subjects (HS) in three-time points (T1-T3). Serum levels of NE, IL-6, IL-8, and CRP in ICU and non-ICU patients were significantly higher than HS (P < 0.001) in three-time points. Also, serum levels of NE, IL-6, IL-8, and CRP in ICU patients were significantly higher than in non-ICU patients (P < 0.05). On the day of admission (T1), the levels of NE, CRP, IL-6, IL-8 were gradually decreased from T1 to T3. At the same time, IL-4 and IL-10 were gradually increased from T1 to T2 and then reduced to T3. Further analyses demonstrated that the levels of NE, IL-6, and IL-8 in deceased patients were significantly higher than in recovered patients (P < 0.05). The ROC curve analysis demonstrated that markers, including NE, IL-6, and IL-8, were valuable indicators in evaluating the activity of COVID-19. Overall, our results signify the critical role of NE in the pathogenesis of COVID-19, and also, further support that NE has a potential therapeutic target for the attenuation of COVID-19 severity.

Stability of SARS-CoV-2 as consequence of heating and microwave processing in meat products and bread.

The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that was first found in 2019 in Wuhan, China, caused coronavirus disease 2019 (COVID-19). It then spread worldwide rapidly, causing the 2019-2020 coronavirus pandemic. To date, it has been indicated that various transmission ways might be participated in outbreaks of COVID-19. Among these, food products, whether raw or processed, might be carriers for SARS-CoV-2. Therefore, this study was aimed to evaluate the effect of cooking and microwave process of meat products and bread on the stability of SARS-CoV-2. In this regard, sausages and hamburger as meat products and toast bread were inoculated with a viral load of 5.70 log fifty percent tissue culture infective dose (TCID50)/mL in order to create a simulated cross-contamination condition. The results showed that frying of hamburger at 225ºC for about either 6 or 10 min resulted in complete inactivation of SARS-CoV-2. Furthermore, a 5-log decrease in SARS-CoV-2 load was observed in sausages as a consequence of cooking process at 78ºC for either 20 or 30 min. Additionally, the effect of microwave oven at power of 630 watt on stability of SARS-CoV-2 showed that exposing toast bread for either 30 s or 1 min in this power led to a 5-log decrease in SARS-CoV-2 load in the toast bread.

Stability of severe acute respiratory syndrome coronavirus 2 in dairy products.

The present investigation was performed to determine the stability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) under several industrial processing situations in dairies, including pasteurization, freezing, and storage in acidic conditions. Ten treatments were selected, including high-temperature short-time (HTST)-pasteurized low-fat milk, low-temperature long-time-pasteurized low-fat milk, extended shelf life (ESL)-pasteurized low-fat milk, HTST-pasteurized full-fat milk, LTLT-pasteurized full-fat milk, ESL-pasteurized full-fat milk, pasteurized cream, ice cream frozen and stored at -20 or -80°C, and Doogh (as a fermented milk drink with initial pH < 3.5) refrigerated for 28 days. The viral particles were quantified by RT-PCR methodology. Besides, the virus infectivity was assessed through fifty-percent tissue culture infective dose (TCID50) assay. These products were seeded with a viral load of 5.65 log TCID50/mL as a simulated cross-contamination condition. Pasteurization techniques were sufficient for complete inactivation of the SARS-CoV-2 in the most dairy products, and 1.85 log TCID50/mL virus reduction in full-fat milk (fat content = 3.22%). Freezing (either -20°C or -80°C) did not result in a virally safe product within 60 days of storage. Storage at high acidic conditions (initial pH < 3.5) completely hampered the viral load at the end of 28 days of refrigerated storage. This research represents an important practical achievement that the routine HTST pasteurization in dairies was inadequate to completely inactivate the viral load in full-fat milk, probably due to the protective effect of fat content. Furthermore, freezing retain the virus infectivity in food products, and therefore, relevant contaminated foods may act as carriers for SARS-CoV-2.

The risk factors and related hospitalizations for cases with positive and negative COVID-19 tests: A case-control study.

BACKGROUND: The aim of this study was to evaluate the risk factors for hospitalizations of cases with positive and negative COVID-19 tests. METHODS: In this case-control study, the case and control groups consisted of 292 COVID-19 patients and 296 non-COVID-19 patients. Patients who referred to a reference laboratory in Tehran (Iran) in March 2020 were selected and interviewed. The patients were contacted by telephone and data were recorded through a questionnaire. RESULTS: The sample of this study consisted of 588 patients (349 [59%] females, 239 [41%] males) with a mean age of 42 ± 15. The results of this study showed that comorbidities like diabetes (OR = 7.42), hypertension (OR = 4.85), asthma and respiratory diseases (OR = 5.64) in addition to symptoms including fever (OR = 6.67), chills (OR = 11.2), anorexia (OR = 11.3), dyspnea (OR = 4.8), weakness and lethargy (OR = 5.7) were the most predictive variables for hospitalization of non-COVID-19 cases. Furthermore, demographical variables like male gender (OR = 3.71), high age (>50; OR = 3.12), BMI (>25; OR = 2.37), travel (OR = 2.79), comorbidities including diabetes (OR = 5.26), hypertension (OR = 3.7) and underlying immunosuppressant patients receiving corticosteroid therapy (OR = 3.62) in addition to symptoms like anorexia [OR = 2.55] and dyspnea (OR = 6.99) tend to increase the risk of hospital admission in COVID-19 patients, suggesting their predictive values for hospitalization of COVID-19 patients. CONCLUSION: Our results indicated that different factors tend to increase the odds of hospital admission in patients with positive and negative COVID-19 tests, suggesting their predictive values for hospitalization.

Bioinformatic HLA Studies in the Context of SARS-CoV-2 Pandemic and Review on Association of HLA Alleles with Preexisting Medical Conditions.

After the announcement of a new coronavirus in China in December 2019, which was then called SARS-CoV-2, this virus changed to a global concern and it was then declared as a pandemic by WHO. Human leukocyte antigen (HLA) alleles, which are one of the most polymorphic genes, play a pivotal role in both resistance and vulnerability of the body against viruses and other infections as well as chronic diseases. The association between HLA alleles and preexisting medical conditions such as cardiovascular diseases and diabetes mellitus is reported in various studies. In this review, we focused on the bioinformatic HLA studies to summarize the HLA alleles which responded to SARS-CoV-2 peptides and have been used to design vaccines. We also reviewed HLA alleles that are associated with comorbidities and might be related to the high mortality rate among COVID-19 patients. Since both genes and patients' medical conditions play a key role in both severity of the disease and the mortality rate in COVID-19 patients, a better understanding of the connection between HLA alleles and SARS-CoV-2 can provide a wider perspective on the behavior of the virus. Such understanding can help scientists, especially in terms of protecting healthcare workers and designing effective vaccines.

Probiotic-Based Vaccines May Provide Effective Protection against COVID-19 Acute Respiratory Disease.

Severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2) infection, the causative agent of COVID-19, now represents the sixth Public Health Emergency of International Concern (PHEIC)-as declared by the World Health Organization (WHO) since 2009. Considering that SARS-CoV-2 is mainly transmitted via the mucosal route, a therapy administered by this same route may represent a desirable approach to fight SARS-CoV-2 infection. It is now widely accepted that genetically modified microorganisms, including probiotics, represent attractive vehicles for oral or nasal mucosal delivery of therapeutic molecules. Previous studies have shown that the mucosal administration of therapeutic molecules is able to induce an immune response mediated by specific serum IgG and mucosal IgA antibodies along with mucosal cell-mediated immune responses, which effectively concur to neutralize and eradicate infections. Therefore, advances in the modulation of mucosal immune responses, and in particular the use of probiotics as live delivery vectors, may encourage prospective studies to assess the effectiveness of genetically modified probiotics for SARS-CoV-2 infection. Emerging trends in the ever-progressing field of vaccine development re-emphasize the contribution of adjuvants, along with optimization of codon usage (when designing a synthetic gene), expression level, and inoculation dose to elicit specific and potent protective immune responses. In this review, we will highlight the existing pre-clinical and clinical information on the use of genetically modified microorganisms in control strategies against respiratory and non-respiratory viruses. In addition, we will discuss some controversial aspects of the use of genetically modified probiotics in modulating the cross-talk between mucosal delivery of therapeutics and immune system modulation.

A possible pathogenic role of Syndecan-1 in the pathogenesis of coronavirus disease 2019 (COVID-19).

A cell-surface heparan proteoglycan called Syndecan-1 (SDC-1) has multiple roles in healthy and pathogenic conditions, including respiratory viral infection. In this study, we explore the dynamic alternation in the levels of SDC-1 in cases with COVID-19. A total of 120 cases definitely diagnosed with COVID-19 were admitted to the Firoozgar Hospital, Tehran, Iran, from December 1, 2020, to January 29, 2021, and included in our study. Also, 58 healthy subjects (HS) were chosen as the control group. Patients were classified into two groups: 1) ICU patients and (63 cases) 2) non-ICU patients (57 cases). The dynamic changes of serum SCD-1, CRP, IL-6, IL-10, IL-18, and Vit D levels a well as the disease activity were investigated in three-time points (T1-T3). Our results indicated that the COVID-19 patients had significantly increased SCD-1, CRP, IL-6, IL-10, and IL-18 levels than in HS, while the Vit D levels in COVID-19 patients were significantly lower than HS. Further analysis demonstrated that the SCD-1, CRP, IL-6, IL-10, and IL-18 levels in ICU patients were significantly higher than in non-ICU patients. Tracking dynamic changes in the above markers indicated that on the day of admission, the SCD-1, CRP, IL-6, IL-10, and IL-18 levels were gradually increased on day 5 (T2) and then gradually decreased on day 10 (T3). ROC curve analysis suggests that markers mentioned above, SDC-1, IL-6, and IL-18 are valuable indicators in evaluating the activity of COVID-19. All in all, it seems that the serum SDC-1 levels alone or combined with other markers might be a good candidate for disease activity monitoring.

The emerging role of probiotics as a mitigation strategy against coronavirus disease 2019 (COVID-19).

COVID-19 is an acute respiratory infection accompanied by pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has affected millions of people globally. To date, there are no highly efficient therapies for this infection. Probiotic bacteria can interact with the gut microbiome to strengthen the immune system, enhance immune responses, and induce appropriate immune signaling pathways. Several probiotics have been confirmed to reduce the duration of bacterial or viral infections. Immune fitness may be one of the approaches by which protection against viral infections can be reinforced. In general, prevention is more efficient than therapy in fighting viral infections. Thus, probiotics have emerged as suitable candidates for controlling these infections. During the COVID-19 pandemic, any approach with the capacity to induce mucosal and systemic reactions could potentially be useful. Here, we summarize findings regarding the effectiveness of various probiotics for preventing virus-induced respiratory infectious diseases, especially those that could be employed for COVID-19 patients. However, the benefits of probiotics are strain-specific, and it is necessary to identify the bacterial strains that are scientifically established to be beneficial.

Abdominal Surgery in Patients With COVID-19: Detection of SARS-CoV-2 in Abdominal and Adipose Tissues.

Multiple tissue samples were obtained during emergent abdominal surgery in 4 patients with coronavirus disease 2019 (COVID-19) to examine for tissue involvement by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first patient underwent a laparoscopic cholecystectomy for gallbladder empyema and died from severe respiratory failure. The second patient with Crohn disease underwent emergent laparotomy for a perforation in the terminal ileum and recovered. The third patient underwent an open appendectomy and recovered. The fourth patient underwent emergent laparotomy for a perforated peptic ulcer and died from sepsis. Although the SARS-CoV-2 RNA was found in the feces of 3 patients and in the duodenal wall of the patient with perforated peptic ulcer, real time reverse transcriptase polymerase chain reaction (RT-PCR) examination of abdominal fluid was negative for the virus. The RT-PCR did not detect viral RNA in the wall of small intestine, appendix, gallbladder, bile, liver, and urine. Visceral fat (omentum) and abdominal subcutaneous fat of 4 patients were also not infected with the SARS-CoV-2. Although this limited experience did not show direct involvement of abdominal fluid and omentum, assessment in large series is suggested to provide answers about the safety of abdominal surgery in patients with COVID-19.

The emerging role of microRNAs in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

The novel coronavirus disease 2019 (COVID-19) pandemic has imposed significant public health problems for the human populations worldwide after the 1918 influenza A virus (IVA) (H1N1) pandemic. Although numerous efforts have been made to unravel the mechanisms underlying the coronavirus, a notable gap remains in our perception of the COVID-19 pathogenesis. The innate and adaptive immune systems have a pivotal role in the fate of viral infections, such as COVID-19 pandemic. MicroRNAs (miRNAs) are known as short noncoding RNA molecules and appear as indispensable governors of almost any cellular means. Several lines of evidence demonstrate that miRNAs participate in essential mechanisms of cell biology, regulation of the immune system, and the onset and progression of numerous types of disorders. The immune responses to viral respiratory infections (VRIs), including influenza virus (IV), respiratory syncytial virus (RSV), and rhinovirus (RV), are correlated with the ectopic expression of miRNAs. Alterations of the miRNA expression in epithelial cells may contribute to the pathogenesis of chronic and acute airway infections. Hence, analyzing the role of these types of nucleotides in antiviral immune responses and the characterization of miRNA target genes might contribute to understanding the mechanisms of the interplay between the host and viruses, and in the future, potentially result in discovering therapeutic strategies for the prevention and treatment of acute COVID-19 infection. In this article, we present a general review of current studies concerning the function of miRNAs in different VRIs, particularly in coronavirus infection, and address all available therapeutic prospects to mitigate the burden of viral infections.

SARS-CoV-2 antibody seroprevalence in the general population and high-risk occupational groups across 18 cities in Iran: a population-based cross-sectional study.

BACKGROUND: Rapid increases in cases of COVID-19 were observed in multiple cities in Iran towards the start of the pandemic. However, the true infection rate remains unknown. We aimed to assess the seroprevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 18 cities of Iran as an indicator of the infection rate. METHODS: In this population-based cross-sectional study, we randomly selected and invited study participants from the general population (from lists of people registered with the Iranian electronic health record system or health-care centres) and a high-risk population of individuals likely to have close social contact with SARS-CoV-2-infected individuals through their occupation (from employee lists provided by relevant agencies or companies, such as supermarket chains) across 18 cities in 17 Iranian provinces. Participants were asked questions on their demographic characteristics, medical history, recent COVID-19-related symptoms, and COVID-19-related exposures. Iran Food and Drug Administration-approved Pishtaz Teb SARS-CoV-2 ELISA kits were used to detect SARS-CoV-2-specific IgG and IgM antibodies in blood samples from participants. Seroprevalence was estimated on the basis of ELISA test results and adjusted for population weighting (by age, sex, and city population size) and test performance (according to our independent validation of sensitivity and specificity). FINDINGS: From 9181 individuals who were initially contacted between April 17 and June 2, 2020, 243 individuals refused to provide blood samples and 36 did not provide demographic information and were excluded from the analysis. Among the 8902 individuals included in the analysis, 5372 had occupations with a high risk of exposure to SARS-CoV-2 and 3530 were recruited from the general population. The overall population weight-adjusted and test performance-adjusted prevalence of antibody seropositivity in the general population was 17·1% (95% CI 14·6-19·5), implying that 4 265 542 (95% CI 3 659 043-4 887 078) individuals from the 18 cities included were infected by the end of April, 2020. The adjusted seroprevalence of SARS-CoV-2-specific antibodies varied greatly by city, with the highest estimates found in Rasht (72·6% [53·9-92·8]) and Qom (58·5% [37·2-83·9]). The overall population weight-adjusted and test performance-adjusted seroprevalence in the high-risk population was 20·0% (18·5-21·7) and showed little variation between the occupations included. INTERPRETATIONS: Seroprevalence is likely to be much higher than the reported prevalence of COVID-19 based on confirmed COVID-19 cases in Iran. Despite high seroprevalence in a few cities, a large proportion of the population is still uninfected. The potential shortcomings of current public health policies should therefore be identified to prevent future epidemic waves in Iran. FUNDING: Iranian Ministry of Health and Medical Education. TRANSLATION: For the Farsi translation of the abstract see Supplementary Materials section.

Effect of Arbidol (Umifenovir) on COVID-19: a randomized controlled trial.

BACKGROUND: Treatment of patients with COVID-19 has included supportive care to mainly relief symptoms of the disease. Although World Health Organization (WHO) has not recommended any effective treatments for COVID-19, there are some reports about use of antiviral drugs. The aim of this study is to determine the effect of Arbidol (ARB) on COVID-19 disease. METHODS: Using an open-label randomized controlled trial, we examined the efficacy of ARB in patients with COVID-19 in a teaching hospital. One hundred eligible patients with diagnosis of COVID-19 were recruited in the study and assigned randomly to two groups of either hydroxychloroquine followed by KALETRA (Lopinavir/ritonavir) or hydroxychloroquine followed by ARB. The primary outcome was hospitalization duration and clinical improvement 7 days after admission. The criteria of improvement were relief of cough, dyspnea, and fever. Time to relief from fever was also assessed across the two groups. Without any dropouts, 100 patients were entered into the study for the final analysis at significance level of 0.05. RESULTS: The mean age of patients was 56.6 (17.8) years and 56.2 (14.8) years in ARB and KALETRA groups, respectively. Majority of patients were male across two groups (66 and 54%). The duration of hospitalization in ARB group was significantly less than KALETRA arm (7.2 versus 9.6 days; P = 0.02). Time to relief fever was almost similar across two groups (2.7 versus 3.1 days in ARB and KALETRA arms, respectively). Peripheral oxygen saturation rate was significantly different after 7 days of admission across two groups (94% versus 92% in ARB and KALETRA groups respectively) (P = 0.02). Based on multiple linear regression analysis, IHD, Na level, and oxygen saturation at the time of admission and type of therapy were the independent adjusted variables that determined the duration of hospitalization in patients with COVID-19. CONCLUSION: Our findings showed that Arbidol, compared to KALETRA, significantly contributes to clinical and laboratory improvements, including peripheral oxygen saturation, requiring ICU admissions, duration of hospitalization, chest CT involvements, WBC, and ESR. We suggest further studies on ARB against COVID-19 using larger sample size and multicenter design. TRIAL REGISTRATION: IRCT20180725040596N2 on 18 April 2020.

Overview of the current promising approaches for the development of an effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine.

Coronavirus disease 2019 (COVID-19) is a pandemic infectious disease caused by the novel coronavirus called SARS-CoV-2. There is a gap in our understanding regarding the immunopathogenesis of COVID-19. However, many clinical trials are underway across the world for screening effective drugs against COVID-19. Nevertheless, currently, no proven effective therapies for this virus exists. The vaccines are deemed as a significant part of disease prevention for emerging viral diseases, since, in several cases, other therapeutic choices are limited or non-existent, or that diseases result in such an accelerated clinical worsening that the efficacy of treatments is restricted. Therefore, effective vaccines against COVID-19 are urgently required to overcome the tremendous burden of mortality and morbidity correlated with SARS-CoV-2. In this review, we will describe the latest evidence regarding outstanding vaccine approaches and the challenges for vaccine production.

Bacterial co-infections with SARS-CoV-2.

The pandemic coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected millions of people worldwide. To date, there are no proven effective therapies for this virus. Efforts made to develop antiviral strategies for the treatment of COVID-19 are underway. Respiratory viral infections, such as influenza, predispose patients to co-infections and these lead to increased disease severity and mortality. Numerous types of antibiotics such as azithromycin have been employed for the prevention and treatment of bacterial co-infection and secondary bacterial infections in patients with a viral respiratory infection (e.g., SARS-CoV-2). Although antibiotics do not directly affect SARS-CoV-2, viral respiratory infections often result in bacterial pneumonia. It is possible that some patients die from bacterial co-infection rather than virus itself. To date, a considerable number of bacterial strains have been resistant to various antibiotics such as azithromycin, and the overuse could render those or other antibiotics even less effective. Therefore, bacterial co-infection and secondary bacterial infection are considered critical risk factors for the severity and mortality rates of COVID-19. Also, the antibiotic-resistant as a result of overusing must be considered. In this review, we will summarize the bacterial co-infection and secondary bacterial infection in some featured respiratory viral infections, especially COVID-19.

Coronavirus disease 2019 (COVID-19): Immunological approaches and emerging pharmacologic treatments.

The SARS-CoV-2 virus is an etiological agent of pandemic COVID-19, which spreads rapidly worldwide. No proven effective therapies currently exist for this virus, and efforts to develop antiviral strategies for the treatment of COVID-19 are underway. The rapidly increasing understanding of SARS-CoV-2 virology provides a notable number of possible immunological procedures and drug targets. However, gaps remain in our understanding of the pathogenesis of COVID-19. In this review, we describe the latest information in the context of immunological approaches and emerging current antiviral strategies for COVID-19 treatment.