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Hepatitis BOctober 2021Summary reviewed May 2026

A New Hepatitis B Vaccine Protected 90% of Adults After Just 2 Doses

This 2,838-adult trial compared a 3-antigen hepatitis B vaccine (PreHevbrio) with the older single-antigen vaccine (Engerix-B) in adults 18-45. After two doses, 90% on the new vaccine had protective antibody levels vs. 52% on the old vaccine.

What the trial was testing

The trial enrolled 2,838 patients with hepatitis b. The study was sponsored by VBI Vaccines and tracked outcomes across the full group of patients who matched the trial's eligibility profile.

It was a large trial designed to confirm whether the treatment works well enough for wider use. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.

What the results showed

90% protected after just 2 doses on the 3-antigen vaccine vs. 52%.

JAMA Network Open · 2021 · NCT03408730

These findings — that protected after 2 vaccine doses on the 3-antigen vs. single-antigen hepatitis B vaccine — were published in the JAMA Network Open and represent the headline result of the study.

Researchers tracked outcomes across 2,838 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.

What this means for patients

For patients with hepatitis b, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.

What you can do now

PreHevbrio (the 3-antigen vaccine) is FDA-approved and available now for adults 18 and older. It works faster than the older single-antigen vaccine. Ask your primary care doctor whether you should get vaccinated, especially if you have diabetes, HIV, kidney disease, or other risk factors.

Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.