Low efficiency of active immunization against diphtheria in chronic hemodialysis patients.

Recent epidemiological studies indicate a low immunity to diphtheria in adults in industrialized countries. In the light of the epidemic increase of diphtheria in countries such as Russia and the Ukraine, systematic vaccination against this disease is recommended. We analyzed the immunity to diphtheria of 228 hemodialysis patients and the efficiency of single versus triple vaccination against diphtheria. Antibodies against diphtheria toxoid were determined by enzyme immunoassay in sera of 228 adult hemodialysis patients. Fifty-four patients were triple vaccinated against diphtheria and were followed for six months; 17 patients were single immunized and antitoxoid titers were determined 1 and 12 months later. The overall protection rate against diphtheria was 22% and equal in male and female patients. After triple immunization, only 35% of the patients developed protective antibody concentration (> 0.1 i.e./ml) six months after the third vaccination. A single vaccination caused protective titres twelve months later in 41% of the patients. There was no difference between responders and non-responders in the duration, intensity or modality of hemodialysis treatment or the response to previous vaccinations against hepatitis-B. We suggest to monitor antibodies against diphtheria toxoid in vaccinated hemodialysis patients at risk for diphtheria since protective titers are often not attained by the standard vaccination protocol.