Comparative Efficacy, Safety and Immunogenicity of Hepavax-Gene TF and Engerix-B Recombinant Hepatitis B Vaccines in Neonates in China.

BACKGROUND: The aim of the study was to compare efficacy, immunogenicity and safety of Hepavax-Gene TF (thimerosal-free) vaccine with comparator in Chinese neonates.

METHODS: A double-blind, randomized, parallel-group, stratified study was conducted at multiple sites in China in healthy neonates, consisting of 3 doses of Hepavax-Gene TF or Engerix-B vaccines administered at birth, 1 and 6 months of age, with a 6-month follow-up after vaccination. On the basis of hepatitis B virus (HBV) infection status of mothers, infants were assigned to one of 2 study strata for mothers positive for HBV infection (stratum 1), with or without active replicating virus (substrata 1a, 1b), and for HBV negative mothers (stratum 2).

RESULTS: Mother-to-child HBV transmission was prevented in >95% of neonates immunized with Hepavax-Gene TF in stratum 1 at all timepoints and was noninferior to Engerix-B. Seroprotection rates (anti-HBs antibody ≥10 IU/L) at 1 and 6 months postvaccination for Hepavax-Gene TF were over 90% for all exposed neonates. Immunogenicity of Hepavax-Gene was noninferior to Engerix-B except for neonates in substratum 1a at 12 months. Geometric mean concentrations between vaccine groups were not significantly different for neonates at all timepoints except in substratum 1b at 7 months. Both vaccines were well tolerated and had similar local and systemic adverse event profiles.

CONCLUSIONS: Hepavax-Gene TF vaccine was equally effective and noninferior to Engerix-B in terms of prevention of mother-to-child HBV transmission in neonates born to mothers positive for hepatitis B surface antigen. Both vaccines elicited seroprotective levels in >90% of all exposed neonates at 12-month follow-up. Both vaccines were well tolerated with similar adverse event profiles.