Hepatitis B virus (HBV) revaccination in MSM who were born in the nationwide neonatal HBV vaccination era: A randomized clinical trial

Objectives Waning immunity and reduced vaccine effectiveness among people with HIV (PWH) raise concerns about optimal HBV revaccination dosing. This study compared double-dose versus standard-dose HBV revaccination among men who have sex with men (MSM) born in the neonatal HBV vaccination era in Taiwan. Methods In this multicenter randomized trial, 526 participants negative for all HBV seromarkers received either standard-dose (20 µg) or double-dose (40 µg) aluminum-adjuvanted recombinant vaccine at Weeks 0, 4, and 24. The primary outcome was seroprotection response (SPR, ≥10 mIU/mL) at Week 28; secondary outcomes included SPR at Week 48 and high-level seroprotection response (HSPR, ≥100 mIU/mL) at Weeks 28 and 48. Results In the per-protocol analysis, SPRs at Week 28 were 92.2% in the standard-dose group vs 96.7% in the double-dose group (difference 4.5%, 95% CI: 0.5-8.4%, P = 0.029), not meeting the superiority threshold. At Week 48, HSPR was higher with double-dose vaccination (74.8% vs 62.8%; difference 11.9%, 95% CI: 3.9-20.0%, P = 0.004). Among PWH, the double-dose group achieved higher HSPR at Weeks 28 (difference 9.0%, 95% CI: 1.0-16.9%) and 48 (difference 11.7%, 95% CI: 1.5-21.9%). Conclusion Both dosing regimens were highly effective. Double-dose HBV revaccination provided stronger and durable high-level protection.