Physical exercise as immune adjuvant: review

Abstract

The use of adjuvants in order to enhance the eff ect of vaccines has been the focus of several research studies. However, some substances with the potential of being used as adjuvants may exhibit high toxicity and side eff ects. In this sense, new methods which are less invasive and more eff ective to perform this function are being developed. Thus, several studies have investigated the eff ects of exercise on immune parameters. It is suggested that physical activities can improve the immune response and may even act as exogenous adjuvants, increasing the host’s immune response effi ciency after vaccination. Therefore, the objective of this study was to review the literature in order to fi nd out how diff erent types, intensities and duration of exercise can act as adjuvants for immunization. To this end, studies that investigated the eff ects of diff erent exercise modalities or protocols were selected, all of them investigating the eff ectiveness of immunization after vaccination, both in humans and in animal models. Regarding exercise intensity, there is a consensus that moderate activities increase the effi cacy of vaccines, while light intensities do not cause any eff ect. Acute sessions of resistance exercise for upper limbs demonstrated to be eff ective for immunization of young people, while for the elderly, such effi cacy was observed with the regular practice of aerobic exercise at a moderate intensity. In conclusion, from what has been observed in the literature, it seems to exist some evidence that physical exercise can be used as a complement to vaccination, especially when it comes to immunization of the elderly.