The Compression of morbidity paradigm envisions reduction in cumulative lifetime morbidity through primary prevention by postponing the age of onset of morbidity to a greater amount than life expectancy is increased, largely by reducing the lifestyle health risks which cause morbidity and disability. Recent data document slowly improving age-specific health status for seniors, indicate that postponement of the onset of disability by at least 10 years is feasible, and prove effectiveness of some lifestyle interventions by randomized controlled trials. Human aging is increasingly represented by frailty, with declining reserve function of many organ systems, including the immune system. Enhancement of immune function in this setting raises medical, ethical, and social issues which are sometimes in conflict.