Safety and immunogenicity of HBAI 20 Hepatitis B vaccine in healthy naïve and nonresponding adults

Summary Approximately 5% of the healthy adult population respond inadequately to the commercial recombinant hepatitis B vaccines. As the recombinant vaccines all have an aluminium‐based adjuvant, we tried to enhance the immune response by adding a cytokine‐based adjuvant. This new adjuvant AI 20, containing 20 μg recombinant human IL ‐2 attached to 20 μg aluminium hydroxide, was added to HBV axPro©‐10 μg ( HBAI 20). In a double‐blind randomized controlled trial ( RCT ), 24 naïve subjects were randomized to receive either HBAI 20 or commercial HBV axPro©‐10 μg vaccine. In an open‐label study, 10 nonresponders received HBAI 20 vaccine. All participants received 3 vaccinations (0, 1 and 6 months). In the RCT , the occurrence of any adverse events or severe events was similar between the trial arms. At month 7, all naïve participants were seroprotected; moreover, 92% in the HBAI 20 group had protective antibodies 10 days after the second vaccination vs 58% in the HBV axPro©‐10 μg group, P  = .16. In the open‐label study, no serious adverse events were noted. The HBAI 20 vaccine was able to elicit protective anti‐ HB s titres in 90% of nonresponders, 1 month after the third vaccination. According to these results, the new HBAI 20 vaccine seems safe, well‐tolerated and may promote more rapid protection against hepatitis B infection.