Figure 2.

The schematic diagram illustrates COVID-19 infection in the human body, followed by rapid spread from viral sanctuary sites. Early innate host immune response dictates viral load at the acute phase. Photobiomodulation therapy (PBMT) acts on transmembrane receptors present in the mitochondria with specific cellular functions, modulating cells with functional deficits, such as blood cells and lung tissue, promoting signaling by the absorptivities of electromagnetic rays. These chromophores convert electromagnetic energy into adenosine triphosphate, and then induce increased macrophage activity, modulation of plasma hormone levels, decreased proinflammatory cytokines, modulated expression of IgA, IgM, and IgG immunoglobulins, and increase of the HbNO synthesis. The results are positive with the synthesis of cytotoxic molecules to microbial membranes, which leads to the destruction of microorganisms of all types in the blood and cytoprotective effect to human cells.