Response to single dose hepatitis B vaccine in Congolese non-HIV hemodialysis patients: a prospective observational study.

Introduction: Because of the cost, in the hemodialysis centers of Kinshasa, the double dose of hepatitis B (HBV) vaccine is administered only to HIV infected patients while other patients receive a single dose. This study aimed to evaluate the single-dose vaccination Protocol and identify determinants of seroconversion's lack of anti-HBs after vaccination schedule.

Methods: 56 non-HIV chronic hemodialysis patients serologically negative for HBs Ag, anti-HBs and anti-HBc were selected between January 2014 and December 2016. The recombinant DNA vaccine (Euvax B20 μg) was administered intramuscularly in the deltoid muscle at days 0, 30, 60 and 180. Serum anti-HBs titer was assayed at day 240. The endpoint was seroconversion, defined as anti-HBs titer ≥ 10 IU/l (10-99 IU/l = low protective vaccine response; ≥ 100 IU/l = highly protective vaccine response). Anti-HBs titer < 10 IU/l defined a lack of seroconversion. A Logistic regression model was used to identify factors associated with the lack of seroconversion.

Results: In the study group (mean age 55.6± 15.1 years; 73 % men, 36% diabetic and 86% hypertensive), low and highly protective vaccine responses were seen in 32% and 50% respectively versus 18% of patient had a lack of seroconversion. CRP > 6 mg/L (aOR: 8.96), hypoalbuminemia (aOR: 6.50) and KT/V < 1.2 (aOR: 3.70) were associated with the lack of seroconversion.

Conclusion: Half of the patients in the study had either a lack or low protective vaccine response. Patient-related factors and hemodialysis parameters were the main factors associated with the lack of anti-HbS seroconversion. These results highlight the need to maximize doses of vaccine in all patients.