Vaccines in Humoral Primary Immunodeficiencies

Vaccines in humoral immunodeficiencies play a pivotal role both in prevention and diagnosis. Due to the generally severe course of infections and to the poor response to conventional antimicrobial treatments, individual prevention through vaccination, as well as protection through herd immunity, is crucial in this population. However, some fundamental issues regarding safety and efficacy have to be stressed. In particular, focus should be put on the increased hazard of vaccine-induced infection, on the potentially lower immunogenicity, and on the susceptibility to specific pathogens. The aim of this chapter is to offer a general approach both to prophylactic and diagnostic vaccination in patients with humoral immunodeficiencies based on literature review and practical experience. In recent years we are witnessing the rapid identification of new diseases and causative genes. For this reason, it is the aim of the authors to offer general principles that could be applicable also into newly discovered clinical entities instead of focusing on specific defects. Specific recommendations will be made only regarding well-defined and studied conditions. Viable and nonviable vaccines will be analyzed separately as well as vaccination in defined patient groups (e.g., patients receiving immunoglobulin, immunomodulatory drugs or transplant, household contacts, travelers, and pregnant women). Besides their prophylactic use, vaccination also plays a pivotal role as diagnostic tool in humoral immunodeficiencies; a practical approach to the evaluation of specific antibody production will be briefly presented at the end of this chapter.