USE OF LICENSED VACCINES FOR ACTIVE IMMUNIZATION OF THE IMMUNOCOMPROMISED HOST

The latter part of the 20th century has witnessed an unprecedented ris e in the number of individuals with impaired immunity. This is primari ly attributable to the increased develop ment and use of antineoplasti c therapy for malignancies organ and bone marrow transplantation, and the AIDS epidemic. Individuals with impaired immunity are often at inc reased risk for infections, and they can experience more severe and co mplicated courses of infection. The lack of therapy for a variety of v iruses and the rise in antimicrobial resistance of many pathogens have focused attention on vaccination to prevent infectious diseases. The efficacy of most licensed vaccines has been established in immunocompe tent hosts. However, there is also considerable experience with most v accines in those with impaired immunity. We reviewed the use of licens ed live, inactivated, and polysaccharide vaccines in this group, and s everal themes emerged: (i) most vaccines are less immunogenic in those with impaired immunity han in normal individuals; (ii) live vaccines are generally contraindicated in this group; and (iii) the efficacy of many commonly used vaccines has not been established in people with i mpaired immunity. This review suggests that for most vaccines there ar e little or no efficacy data in those with impaired immunity but their use in this patient group is generally safe.