Balneotherapy in Stimulating Resistance to Infections – the Little-used Health Resort’s Potential During the COVID-19 Pandemic

To function properly, the human immune system must be adequately stimulated. Immune activity is stimulated as a result of the use of vaccines as well as the exposure of the body to infections. This type of stimulation only increases the specific humoral immunity, characterized by relatively short duration, and targeted at a well-defined antigen. In the case of the COVID-19 virus, immune memory cells persist for up to one year. In parallel with specific stimulation, it is necessary to develop non-specific immunity. It is the body’s first line of defense against infection, affects many microorganisms, and supports specific immunity. We can develop and strengthen this immunity using non-pharmacological methods, including balneotherapy, physical activity, and an appropriate diet. There is now much scientific evidence showing the effectiveness of balneotherapy in improving innate immunity. In in vitro and in vivo studies with high scientific credibility, the following effects of balneotherapy on the immune system were demonstrated: stimulation of the proliferation of T lymphocytes (especially CD4), normalization of the ratio between lymphocytes with different cytotoxic and anti-inflammatory effects, increased number of granulocytes and stimulation of the phagocytic activity of granulocytes and macrophages, lowering the concentration of proinflammatory cytokines and stimulating the secretion of anti-inflammatory cytokines, CRP, prostaglandins (PGE2), as well as antioxidant and neurohormonal activity. Among treatments with balneoimmunostimulatory effects, one should mention sulfide baths, peloid compresses, brine baths, radon treatments, and hot baths. These treatments are mainly used as part of health resort treatment. In Poland, health resort treatment represents excellent health potential. Unfortunately, it is very modestly used in activities aimed at improving the immunity of Polish society. This treatment would be best combined in patients after vaccination and in a certain period before vaccination, which would significantly increase the effectiveness of prophylactic vaccinations.