METHODS	An observer-blind , randomized , active-controlled , parallel group , multicenter trial was conducted among 521 patients 18-75 years of age with CKD , comparing 3 single doses of an investigational hepatitis B vaccine ( 20 mcg rHBsAg +3000 mcg 1018 , a toll-like receptor 9 agonist ) given at 0 , 4 , and 24 weeks to 4 double-doses of HBsAg-Eng ( 220 mcg rHBsAg +500 mcg alum ) given at 0 , 4 , 8 , and 24 weeks ( total of 8 injections ) .\