Vaccination with polysaccharide-conjugate-vaccines in adult patients with specific antibody deficiency.

We report on a cohort of seven adult patients with specific antibody deficiency, defined by failure to respond to 23-valent Streptococcus pneumoniae vaccine while being able to respond to tetanus toxoid. Antibodies to Hemophilus influenzae (HiB) polysaccharides either pre-existed or were readily induced by a single vaccination with the HiB-tetanus toxoid conjugate. By contrast a single vaccination with the S. pneumoniae-diphtheria conjugate failed to induce a response to any of the seven serotypes in any of the seven patients. After a second vaccination in six patients, two patients continued to show no response but four showed a 3- to 45-fold response with development of >1 microg/ml of IgG to 2-4 of the serotypes, respectively. The data show that conjugate vaccines can enforce a response in adult patients with selective antibody deficiency but, dependent on the type of polysaccharide-conjugate, repeated immunisation and monitoring of the response is required.