Biomodulina T, the active ingredient in InmunyVital®, is a polypeptide thymic factor that modulates immune responses and inflammation. Biomodulina T stimulates the differentiation, maturation and proliferation of CD3 T cell populations and CD4 and CD8 T cell subpopulations. Additionally, Biomodulina T improves the ability of T cells to produce cytokines, therefore enhancing T lymphocyte function. Additionally, Biomodulina T stimulates the thymus gland and, thus, promotes the recovery of normal thymus mass and size in children with thymic hypoplasia and restores the functions of immunosenescent T cells in aging people.The thymus gland slowly shrinks with age, and the levels of the thymic factors it produces decrease in the blood. Moreover, thymus-dependent immunity, including T cell immunity and thymus- dependent antibody production, decreases with thymus size in adult people. For that reason, older adults are generally at a higher risk of becoming severely ill from infectious diseases, such as influenza, COVID-19 and other diseases. As people age, “immunosenescence” occurs; immunosenescence means that with age, the ability to produce vigorous responses to infections gradually diminishes compared to that observed at younger ages during which the thymus gland, thymic factor levels, and immune responses are healthy and strong. In addition, in older adults, low-grade, chronic systemic inflammation, called “inflamm-aging”, occurs, and this phenomenon increases susceptibility to age-related inflammatory diseases.In 1984, with the aim of developing biological response modifiers, I established the laboratory of Biomodulators in Havana, where I created and developed the immunomodulatory thymic factor that I called “Biomodulina T”. The biological activity of Biomodulina T was demonstrated in several in vitro and in vivo studies in our laboratory and in independent laboratories. An extensive series of preclinical toxicological studies were conducted in different species, such as mice, rats, guinea pigs, rabbits and dogs. All these studies demonstrated that Biomodulina T is an active and safe thymic factor.We conducted clinical trials with Biomodulina T in patients with multiple sclerosis, chronic hepatitis B, rheumatoid arthritis, Crohn's disease, Behcet's syndrome, and selective deficiency of IgA as well as in geriatric populations. In 1994, I obtained the sanitary registration of Biomodulina T as an immunomodulatory drug.Since that time, we conducted other clinical trials in children with repeated infections and primary immunodeficiencies and in adults with systemic lupus erythematosus, uveitis, myasthenia gravis, chronic obstructive pulmonary disease (COPD), and respiratory infections.This article identifies the milestones involved in the creation and development of Biomodulina T. Since its discovery 35 years ago, the first and recent reports of new scientific advances show that Biomodulina T (InmunyVital®) is a modulator of immune responses and inflammation that is very useful for restoring the immune system in young and elderly people with allergies, asthma, immunodeficiency, autoimmune diseases, and infectious diseases. Biomodulina T is also useful as an immunotherapeutic agent for improving immune responses in the context of cancer and vaccines, for reversing immunosenescence and for improving the healthspan in general aging.