The SARS-CoV-2 pandemic has become one of the most serious health concerns globally. Although multiple vaccines have recently been approved for the prevention of coronavirus disease 2019 (COVID-19), an effective treatment is still lacking. Our knowledge of the pathogenicity of this virus is still incomplete. Studies have revealed that viral factors such as the viral load, duration of exposure to the virus, and viral mutations are important variables in COVID-19 outcome. Furthermore, host factors, including age, health condition, co-morbidities, and genetic background, might also be involved in clinical manifestations and infection outcome. This review focuses on the importance of variations in the host genetic background and pathogenesis of SARS-CoV-2. We will discuss the significance of polymorphisms in the ACE-2, TMPRSS2, vitamin D receptor, vitamin D binding protein, CD147, glucose‐regulated protein 78 kDa, dipeptidyl peptidase-4 (DPP4), neuropilin-1, heme oxygenase, apolipoprotein L1, vitamin K epoxide reductase complex 1 (VKORC1), and immune system genes for the clinical outcome of COVID-19.

Scan to discover onlineBackground & Objective: Epstein-Barr virus nuclear antigen-1 (EBNA1) is one of the most important proteins of Epstein-Barr virus (EBV) that might be mutated in various related cancers. The purpose of this study was to compare EBNA1 mutations in the C-terminal region between patients with cervical and ovarian cancer and healthy individuals.Methods: As test and control groups, 18 EBV-positive paraffin-embedded samples of cervical and ovarian cancer and 10 age-and gender-matched healthy volunteers who did not have cancer but were EBV-positive were both used. Utilizing a commercial DNA extraction kit, total DNA was extracted following deparaffinization. The entire C-terminal region of the EBNA1 sequence was amplified using an in-house nested PCR. Phylogenetic analysis and Sanger sequencing were used to analyze the sequences using MEGA 7 software and through NJ method.Results: Sequence analysis revealed that the P-Ala subtype of EBNA1 was present in all samples. In two and one samples, respectively, of cervical cancer patients, the mutations A1887G and G1891A were found. The G1595T mutation was also detected in four sequences taken from ovarian cancer patients. No statistically significant difference could be found between the frequency of mutations in patients and controls (P>0.05). No known amino acid substitutions were found in the USP7-binding region and the DBD/DD domain. Conclusion:The findings showed that P-Ala is the predominant EBV subtype across all samples. Additionally, as the sequence of EBNA1's C-terminal region is so stable, it's possible that it had little impact on the pathogenesis of ovarian and cervical malignancies. It is advised to conduct additional research to verify these findings.

Background: Regarding the availability of an effective vaccine against hepatitis B virus, global vaccination is the best costeffective strategy to prevent HBV infection. However, some people may not respond to the vaccine or the titer of antibody decreases by time. Therefore, the present study aimed to determine the frequency of anti-HBs antibody (anti-HBsAb), among university students in Fars province, southern Iran. Methods: In this cross-sectional study, 825 medical students were enrolled. Blood samples were taken from the subjects, and the serum separated and stored at-20 ºC until use. Next, HBs Ab titer was measured by ELISA method. Results: Out of 825 students 54% was male and 46% were female. The mean age of the students was 19.5±1.9. The titer of anti-HBsAb in 529 (64%) of subjects was lower than 10 mIU/mL. Significant relationship was observed between age and the titer of anti-HBsAb (P=0.001), although no significant relationship was observed between gender (P=0.19), history of blood transfusion (P=0.58) and the titer of anti-HBsAb. Conclusion: Finding of this study showed that the titer of anti-HBsAb in more than half of students was lower than 10 mIU/mL and by time the anti-HBsAb titer decreased, indicating the necessity of measurement of anti-HBsAb titer in medical students.