Tri-Antigenic vs Mono-Antigenic Vaccine for Hepatitis B Virus Prevention

Doctor with protective face mask and gloves is preparing vaccine for HBV – Hepatitis
A team of researchers sought to compare the seroprotection rate of a hepatitis B virus tri-antigenic vaccine with that of a mono-antigenic vaccine in adults.

Compared with a mono-antigenic vaccine (MAV), immunogenicity of a tri-antigenic vaccine (TAV) for hepatitis B virus (HBV) infection was found to be noninferior among adults 18 years of age and older and superior among adults 45 years of age and older, including individuals with stable, controlled chronic conditions, according to study results published in The Lancet Infectious Diseases.

A team of investigators conducted a multicenter, double-blind, phase 3, randomized clinical trial (PROTECT; Identifier: NCT03393754; EudraCT: 2017–001819-36) to compare seroprotection rates of MAV and TAV against HBV in adults with stable and controlled chronic conditions.

From December 2017 to April 2019, participants at hospitals in the United States, Finland, Canada, and Belgium were randomly assigned 1:1 to either TAV (10 μg) or MAV (20 μg) on days 0, 28, and 168. The trial included 6 study visits and 24 weeks of follow-up following the third vaccination. Both vaccines were administered intramuscularly.

The primary outcomes of the study were noninferiority of the seroprotection rate of TAV vs MAV in adults 18 years of age and older, and the superiority of TAV to MAV in patients 45 years of age and older. The vaccine-induced seroprotective rate was defined as the percentage of patients who had hepatitis B surface antibodies (anti-HBs) titers of 10 mIU/mL or more.

Of the 2472 patients who were screened, 1607 patients (62% women) were randomly assigned to receive either TAV (n=796) or MAV (n=811); 18.6% were aged 18 to 44 years, 44.6% were aged 45 to 64 years, and 36.8% were 65 years and older.

Seroprotection rates were 91.4% for recipients of TAV and 76.5% for recipients of MAV 18 years and older, suggesting noninferiority of TAV (difference, 14.9%). Seroprotection rates in participants 45 years and older in the TAV and MAV groups were 89.4% and 73.1%, respectively, suggesting superiority of TAV compared with MAV (difference, 16.4%).

Compared with MAV, recipients of TAV experienced more solicited local adverse events including any solicited local adverse event (71.9%; P <.0001), pain (63.2%, P <.0001), and tenderness (60.8%, P <.0001). Significant solicited systemic adverse events in the TAV group compared with the MAV group included any systemic adverse event (55.9%, P =.02) and myalgia (P =.008).

“The ability of TAV to safely seroprotect more adults earlier following fewer vaccinations in adults aged 18 [to] 44 years, including those with impaired vaccine immune responses in individuals with well-controlled comorbidities, shows its potential to overcome the limitations of current standard MAVs and to help address ongoing unmet medical needs in the prevention of HBV infection,” the authors noted.

Disclosure: This research was supported by VBI Vaccines. Please see the original reference for a full list of disclosures.


Vesikari T, Langley JM, Segall N, et al; PROJECT Study Group. Immunogenicity and safety of a tri-antigenic versus a mono-antigenic hepatitis B vaccine in adults (PROTECT): a randomised, double-blind, phase 3 trial. Lancet Infect Dis. Published online May 11, 2021. doi:10.1016/S1473-3099(20)30780-5