title: Evaluation of thimerosal removal on immunogenicity of aluminum salts adjuvanted recombinant hepatitis B vaccine.
abstract: Thimerosal, which is approximately 50% mercury by weight is a preservative widely used in vaccines since the 1930's. It meets the requirements for a preservative as set forth by Pharmacopeia challenge test and has been shown to be effective against a broad spectrum of pathogens. In July 1999, the Public Health Service agencies and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines as a precautionary measure but, due to the lack of appropriate alternative, it is still extensively used in multiple dose formulations of vaccines such as hepatitis-B in developing countries. In this study the effect of the removal of thimerosal in two formulations of hepatitis B vaccines containing either aluminum hydroxide or aluminum phosphate were evaluated in Balb/c mice. These formulations were administered interperitoneally and the titer of antibody was determined by ELISA technique after 28 days. The geometric mean of antibody titer (GMT), seroconversion and seroprotection rates, ED50 and relative potency of different formulations were determined. The ED50 of thimerosal-free formulations were reduced by more than 35% in both preparations. In addition, GMT of antibody titer, seroconversion and seroprotection indicated significantly higher immunogenicity for thimerosal free formulations for both aluminum phosphate and hydroxide adjuvants.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Mahboubi
authors.affiliation: Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Fazeli
authors.affiliation: Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Samadi
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences.
authors.forename: Rasoul
authors.initials: R
authors.lastname: Dinarvand
authors.affiliation: Drarou Pakhsh Pharmaceutical Mfg. Co. Biotech. Research Department Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Azadi
keywords: Aluminum salts; GMT; Hepatitis B vaccine; Relative potency; Thimerosal