Immunization of the immunocompromised patient

In immunocompromised individuals the incidence and severity of vaccine-preventable diseases is particularly high; besides, these patients are at increased risk, as in constant contact with health care environments. Therefore, immunization of immunocompromised individuals is an important prevention tool. However, the safety, immunogenicity, efficacy/effectiveness data for vaccinations in these patients are still limited and vaccination coverage rates in immunocompromised subjects are generally low. In addition, the types of immunodeficiencies are many and with a variable degree of immunological impairment, so it is difficult to have precise and always applicable guidelines. In general, live vaccines are contraindicated in immunocompromised patients, and limited evidence suggests that inactivated vaccines have the same safety profile in both immunocompetent and immunocompromised patients. In theory, therefore, inactivated vaccines can be administered, but the amount and duration of the immune response in immunocompromised patients can be reduced or absent. Depending on the type of immunodeficiency, in fact, various mechanisms of the immune system can be compromised and consequently, according to the pathology, there will be a different response to different vaccines also. Each immunocompromised patient must therefore be evaluated individually, carefully assessing the potential benefit related to the prevention of the disease, the safety, tolerability and efficacy/immunogenicity of immunization, and indications or contraindication to each vaccine. In general, immunization of patients affected by primary or secondary immunodeficiency allows to improve the quality of life and prognosis, to decrease infectious complications and could be a lifesaving intervention. Even if available data highlight the need for further studies on the level of effectiveness of different vaccines in relation to different immunodeficiencies, we absolutely need to increase awareness of the importance of vaccinations in immunocompromised patients.