SARS-CoV-2, a newly emerging coronavirus that caused the COVID-19 epidemic, has been spreading quickly throughout the world. Despite immunization and some fairly effective therapeutic regimens, SARS-CoV-2 has been ravaging patients, health workers, and the economy. SARS-CoV-2 mutates and evolves to adapt to its host as a result of extreme selection pressure. As a consequence, new SARS-CoV-2 variants have emerged, some of which are classified as variants of concern (VOC) because they exhibit greater transmissibility, cause more-severe disease, are better able to escape immunity, or cause higher mortality than the original Wuhan strain. Here, we introduce these VOCs and review their characteristics, such as transmissibility, immune escape, mortality risk, and diagnostics.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the pathogenesis is unclear. Host genetic background is one of the main factors influencing the patients' susceptibility to several viral infectious diseases. This study aimed to investigate the association between host genetic polymorphisms of two genes, including vitamin D receptor (VDR) and vitamin D binding protein (DBP), and susceptibility to COVID-19 in a sample of the Iranian population. This case-control study enrolled 188 hospitalized COVID-19 patients as the case group and 218 suspected COVID-19 patients with mild signs as the control group. The VDR (rs7975232, rs731236 and rs2228570) and DBP (rs7041) gene single nucleotide polymorphisms (SNPs) were genotyped by Polymerase Chain Reaction Restriction -Fragment Length Polymorphism (PCR-RFLP) method. A significant association between rs2228570 SNP in the VDR gene and the susceptibility

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Viral infections have been considered as possible destructive factors that influence male fertility. The aim of this study was to determine the prevalence of human herpes viruses 1-5 (HHV1-5), adeno associated virus (AAV) and human papilloma virus (HPV) in semen and whether these influence semen quality. DNA extraction was performed using phenol-chloroform protocol, then three different nested-PCRs were done to detect HHV1-5, AAV and HPV DNAs in the semen samples. Of 145 samples, 66 (45.5%) were positive at least for one of the viruses. The genome detection rate of HSV1/2, VZV, EBV, HCMV, AAV and HPV were zero, 2.8%, zero, 1.4%, 27.6% and 19.3%, respectively. Of 66 positive samples for these viruses, 6 (4.1% of all samples) were positive for two viruses simultaneously. Here no association was found between variations in semen parameters related to fertility and detection of VZV, HCMV, AAV and HPV DNA in semen samples. It should be noted that the prevalence of different viruses in semen, and their relevance to male infertility, differs significantly due to the genome extraction and amplification methods or due to a real variation between study populations and geographical regions.

Rubella is a mild self-limiting contagious viral disease caused by the rubella virus (RV). Although symptoms are often mild, the concern is centralized around the possible effect on a fetus growth and development in case of primary infection during early months of pregnancy. Recently acquired rubella is commonly confirmed by RV-specific IgM antibody detection in the serum. However, rubella primary infection is not always the only cause of IgM positivity. Other possible causes of rubella IgM positivity may include IgM persistence following vaccination or naturally acquired infection or even re-infection. Moreover, nonspecific IgM reactivity can cause false-positive results. There are few articles to differentiate the aetiology of rash in rubella-like illnesses. However, limited studies have been conducted on clarifying the source of IgM positivity in these cases. This article reports the study of 10,896 clinical cases demonstrating rubella-like illness between 2011 and 2013 in Iran. The rate of IgM positivity among these cases was 0.52% (57 cases). As predicted based on the high coverage of vaccination in Iran fewer than 16% of cases with ELISA IgM positive result, were due to current rubella primary infections. The greater part of the positive IgM reactions occurred in cross reactivity with other viruses (31.6%) or in prolonged IgM response post vaccination (24.6%). This research confirmed that the positive result of rubella IgM assay in vaccinated individuals is mainly caused by prolonged IgM production, rubella re-infection, and false positivity due to infection with other viruses, rather than the rubella primary infection itself.