Introduction : With the rise of biological treatments, the practice of travel medicine become more complex. Moreover, biological treatments are likely to have impact on the risk of infection on population in low-income countries. As a result, the immunosuppressed travellers represent a sentinel population useful to study. Three main burdens stand out: the risk of opportunistic diseases, the safety of live vaccines and vaccine efficacy.

Objectives & Methods : The aim is to present the current knowledge faced by the immunosuppressed traveller. As there is little evidence and most recommendations are based on expert opinion, evidence is needed. Four studies covering the full range of the triple burden are presented below.

Results & discussion : The screening for latent infections allows the diagnosis in immunosuppressed patients, even in a non-endemic country. It is important to carry out screening prior to any immunosuppressive treatment. While the benefit of vaccination is largely accepted in populations suffering from autoimmune diseases, there remain certain contraindications based on a cautious attitude. The observed absence of increased risk of yellow fever vaccination in multiple sclerosis patients in a retrospective study is the first step before larger study. Immunosuppressive treatments, particularly biological treatments, came in wide diversity. Thus, a broad contraindication without considering pharmaco-immunological mechanisms puts at risk a population exposed to complications of vaccine-preventable diseases. While a retrospective review of weakly immunosuppressed patients exposed to live attenuated vaccines provides reassurance of the absence of serious side-effects, a prospective study of a small sample of patients on low-dose methotrexate seems to confirm the absence of a vaccine contraindication in this population, and to observe an effective immune response.

Conclusion : We live in a global society. It is vital to take account of the mobility factor when it comes to infectious diseases and the potential means of preventing. However, while it is essential not to overlook potential risks of vaccination, it is equally important to ensure the protection of vulnerable populations. Given the complexity and heterogeneity of situations, an individualized approach seems necessary.