How can virus affect the whole body?
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea. They are dead outside the living cell.
A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. A virus cannot replicate alone.
The structural proteins of SARS-CoV-2 include membrane glycoprotein (M), envelope protein (E), nucleocapsid protein (N), and the spike protein (S)
The immune response by humans to CoV-2 virus occurs as a combination of the cell-mediated immunity and antibody production, just as with most other infections. Since SARS-CoV-2 has been in the human population only since December 2019, it remains unknown if the immunity is long-lasting in people who recover from the disease.
What happen after getting vaccine in our body?
The presence of neutralizing antibodies in blood strongly correlates with protection from infection, but the level of neutralizing antibody declines with time. Those with asymptomatic or mild disease had undetectable levels of neutralizing antibody two months after infection. In another study, the level of neutralizing antibodies fell four-fold one to four months after the onset of symptoms. However, the lack of antibodies in the blood does not mean antibodies will not be rapidly produced upon re exposure to SARS-CoV-2. Memory B cells specific for the spike and nucleocapsid proteins of SARS-CoV-2 last for at least six months after the appearance of symptoms
SARS-CoV-2 and volatilome production
SARS-CoV-2, the causal virus of COVID-19, is an enveloped positive-stranded RNA virus belonging to the Coronaviridae family, Betacoronavirus genus.
Full-genome sequencing and phylogenic analysis have indicated that the novel virus shares genetic material with the bat coronavirus, SARS-CoV and is more distantly related to Middle east respiratory syndrome- coronavirus MERS-CoV.
What happen when corona virus effect our body?
Similar to SARS-CoV, SARS-CoV-2 mainly operates through its spike S-protein that binds to the human ACE II receptors found in the lower respiratory tract cells, inducing endocytosis.
This fusion is accompanied by a decrease of pH in the endosome that results in uncoating of viral particles and the release of the viral genome in the cytoplasm for protein synthesis. Genome translation produces two large replicase polyproteins, pp1a and pp1ab which are subjected to auto proteolytic processes resulting into the formation of non-structural proteins that ultimately together with recruited host cell proteins, form membrane-associated replication and transcription complexes. Replication and transcription result in the formation of a set of sub genomic RNAs which encode accessory and structural proteins. Newly formed genomic RNA, nucleocapsid proteins and envelope glycoprotein are assembled in the endoplasmic reticulum and the Golgi apparatus and form the viral particle buds that will be released outside the cell into the airways.
How Voc’s help in detection of COVID 19?
The whole process of protein synthesis involves many signal transduction and protein expression pathways with the production and the use of multiple small molecules (cofactors, reactants and side products) that can cross the cell membrane and can possibly be detected in the exhaled breath. Furthermore, since SARS-CoV-2 has a different viral entry receptor than those of influenza or rhinovirus it is thought that it can generate specific VOCs and thus be differentiated from other viruses.
On the other hand, SARS-CoV-2 antigens are presented by the dendritic cells in order to induce humoral and cellular immunity, and form virus-specific B-cells and T-cells. Since HLA gene expression profiles exhibit unique VOCs as an immunological fingerprint based on exposure to a specific antigen, it is expected to have unique and specific VOCs when exposed to SARS-CoV-2.
Storm of Cytokines
Finally, in the unfortunate event of a cytokine storm, an overproduction of inflammatory cytokines with a wide range of biological activity is triggered by a variety of tissues and cells. These cytokines exert a positive feedback on other immune cells to secrete additional inflammatory products. They also serve to attract more immune cells to the site of inflammation inducing an exponential growth of inflammation and organ damage. The main cytokines involved are interleukins (IL), such as IL-1β, IL-6, IL-12, interferons (IFN), mainly IFN-γ, tumour necrosis factor, colony stimulating factors, the chemokine family, growth factors, and others. This cascade of inflammatory processes in reaction to SARS-CoV-2 infection will lead to a lung injury due to destruction of the cellular structure through oxidative stress and lipid peroxidation and will liberate additional distinctive VOCs that could reflect the severity of the damage, mainly organic lipid peroxidation markers.
In point of fact, two previous studies examining volatile markers in exhaled air found higher n-pentane levels and lower isoprene concentration in acute respiratory distress syndrome ARDS patients compared with baseline measurements in healthy individuals. Consequently, specific VOCs in this case could both play a diagnostic and prognostic role.
VOC’s Serves as Biomarkers
Recent research demonstrated that the volatilome could be used to detect diseases, pathogens, and many other unique aspects of an organism. Besa et al stated in the study published in February 2015, that various inflammatory and metabolic processes, either physiological or disease related, may produce VOC.
- These compounds are extremely variable between individuals and their concentrations depend on multiple factors, such as metabolism or systemic physiologies. Moreover, Schmidt and Podmore concluded from their article published in 2015 that many uncontrolled variables, such as genetic differences, environmental settings; diet, drug ingestion and smoking affect VOC patterns, thus, leading to its variation between individuals.
- Therefore, VOC profile is influenced by many different physiological and pathological processes; in other words, not all VOCs released from the body are related to human metabolism, they can be related to the commensal microbiota or from microbial infections. Other VOC may be from foods, drinks, medications, and pollutants. Consequently, the new VOC’s produced or the VOC’s which expression pattern are altered by a disease or an infection may serve as a biomarker.
For all what has been stated, we think that fighting COVID-19 pandemic while keeping the economy alive needs a smart strategy, applying universal screening using tests with good performance, low cost and easy application for large-scale use.
Possible applications of COVID19ATM (Breath Analyser) act as a pathway for COVID-19 tests which able to detect Covid19 within 20 seconds helps in schools reopening, airway passengers screening, religious gatherings and any other situation where rapidly performed, efficient, noninvasive tests are needed with point of care possibility to get immediate results