[Evaluation of immunogenicity and safety in healthy adults of an inactivated anti-hepatitis A vaccine]

Abstract

Background: The evaluation of the safety and immunogenicity of an inactivated vaccine against the hepatitis A virus (HAV) in healthy adults was performed.

Methods: A descriptive clinical trial was carried out including a population of 100 healthy subjects of ages from 19 to 25-years. The subjects were intramuscularly injected (deltoid muscle) with an inactivated vaccine against hepatitis A (720 units ELISA) following a schedule of 0.1 months and a booster dose at 6 months. The titers of anti HAV antibodies were determined by the ELISA method prior to vaccination and following the administration of each doses. The safety of the vaccine was also parallelly evaluated after each doses from both a local and systemic point of view.

Results: With respect to safety, local signs and symptoms were presented in 34.6% of the subjects while systemic signs and symptoms were observed in 6.8% following administration of the 3 doses. At one month of the first doses 95.8% of the subjects had seroconverted (> or = 20 mUI/ml) with this rising to 100% at one month of receiving the second and third doses. The geometric mean of the antibody titer one month after having received each of the three doses was 158 mUI/ml, 832 mUI/ml and 4,135 mUI/ml, respectively.

Conclusions: The vaccine was well tolerated and demonstrated great safety with a 100% rate of seroconversion following the primary cycle with two doses. The administration of the reminder doses at 6 months increased the antibody titer five fold after the primary cycle.