First identified in 2012, Middle East respiratory syndrome (MERS) is caused by an emerging human coronavirus, which is distinct from the severe acute respiratory syndrome coronavirus (SARS-CoV), and represents a novel member of the lineage C betacoronoviruses. Since its identification, MERS coronavirus (MERS-CoV) has been linked to more than 1372 infections manifesting with severe morbidity and, often, mortality (about 495 deaths) in the Arabian Peninsula, Europe, and, most recently, the United States. Human-to-human transmission has been documented, with nosocomial transmission appearing to be an important route of infection. The recent increase in cases of MERS in the Middle East coupled with the lack of approved antiviral therapies or vaccines to treat or prevent this infection are causes for concern. We report on the development of a synthetic DNA vaccine against MERS-CoV. An optimized DNA vaccine encoding the MERS spike protein induced potent cellular immunity and antigen-specific neutralizing antibodies in mice, macaques, and camels. Vaccinated rhesus macaques seroconverted rapidly and exhibited high levels of virus-neutralizing activity. Upon MERS viral challenge, all of the monkeys in the control-vaccinated group developed characteristic disease, including pneumonia. Vaccinated macaques were protected and failed to demonstrate any clinical or radiographic signs of pneumonia. These studies demonstrate that a consensus MERS spike protein synthetic DNA vaccine can induce protective responses against viral challenge, indicating that this strategy may have value as a possible vaccine modality against this emerging pathogen.

Background and Objective: In recent years, respiratory tract viral infections have caused many pandemics that impact the whole world.To investigate the seropositivity of Toxoplasma gondii, rubella, CMV, HSV-1 and group A Streptococcus in recovered COVID-19 patients and correlate these findings with vitamin D levels. Materials and Methods: A total of 417 COVID-19 patients with diarrhoea were enrolled in this study. Vitamin D and seroprevalence for Toxoplasma gondii, rubella, CMV, HSV-1 and group A Streptococcus were evaluated and correlated. Results: It was found that recent infection in COVID-19 patients with HSV-1, rubella, Toxoplasma and CMV, respectively. IgG was detected indicating the development of adaptive immunity with all microbes. Conclusion: Current study detected a correlation between vitamin D levels and HSV-1 and no correlation between this infection and vitamin D deficiency with the other microbes.