The new coronavirus pandemic continues to spread causing further public health, social, and economic issues. The disparities in the rates of death between countries poses questions about the importance of lifestyle habits and the immune status of populations. An exploration of dietary habits and COVID-19-related death might unravel associations between these two variables. Indeed, while both nutritional excess and deficiency are associated with immunodeficiency, adequate nutrition leading to an optimally functioning immune system may be associated with better outcomes with regards to preventing infection and complications of COVID-19, as well as developing a better immune response to other pathogenic viruses and microorganisms. This article outlines the key functions of the immune system and how macronutrients, micronutrients, and metabolites from the gut microbiome can be essential in the development of an efficient immune system. In addition, the effects of intermittent fasting on the inflammatory state as well as metabolic parameters will be discussed. continue reading
In the past two decades, the world has seen the emergence of three novel coronaviruses (CoV) leading to disease outbreaks that have caused considerable global health consternation: the severe acute respiratory syndrome coronavirus (SARS-CoV), the Middle East respiratory syndrome coronavirus (MERS-CoV), and the recently emerged coronavirus SARS-CoV-2.
is the name of a newly identified disease caused by SARS-CoV-2, and it was originally observed as a cluster of atypical pneumonia cases occurring in Wuhan, China, in December 2019 (2).
While this newly identified virus belongs to the same β-coronavirus genus as SARS-CoV and MERS-CoV, the novel disease seems to be characterized not only by mild upper respiratory infections, similar to other corona-viruses, but also by the presence of symptoms of the lower respiratory tract that are sometimes very severe (4).
These mild and even asymptomatic cases have contributed to the silent spread of infections worldwide, increasing the probability of infecting high risk groups of individuals comprising immunocompromised patients and those with chronic diseases (1, 4–12). Indeed, the WHO has estimated the reproductive number (R0)
of the novel infection by SARS-CoV-2 to range between 2 and 2.5, which is higher than SARS (1.7–1.9) and MERS (<1), suggesting from the outset that COVID-19 has a higher pandemic potential. continue reading
Human Coronavirus Infection and the Host's Immune System
Components of the Human Immune System and Lines of Defense Against Viral Infection
The first line of immune defenses includes the physical and chemical barriers that attempt to block the entry of microbes. When these barriers are breached, the microbes will be fought by the components of the internal innate immune system which is composed of leukocytes and defensive proteins that act immediately and non-specifically to eradicate infections (28). If innate immunity fails to eliminate the infection, the adaptive immune system will be activated. T and B lymphocytes are the adaptive immune cells which are able to recognize antigens with high specificity summarizes the major functions of the innate and adaptive immune cells. continue reading