A new triple-antigen vaccine against infection with the hepatitis B virus confers greater protection than the single-antigen Engerix-B vaccine, in adults of all ages and with numerous comorbidities, researchers have found.
More than 2 million people in the United States are estimated to have chronic hepatitis B, yet perhaps only 25% of American adults have been vaccinated against HBV. Although effective, the Engerix-B vaccine (GlaxoSmithKline) is less beneficial for people over 45 years of age or with comorbidities such as obesity or diabetes. VBI Vaccines, which makes the new vaccine, called Sci-B-Vac, applied for FDA approval for the agent in February.
“This vaccine is an improved option for hepatitis B prevention,” said Joanne Langley, MD, the principal investigator on the PROJECT trial, a head-to-head study of Sci-B-Vac and Engerix-B conducted in the United States, Canada, Belgium and Finland. “I would want this vaccine rather than Engerix-B for older patients or those with the risk factors we studied.”
Langley, the head of infectious diseases at Dalhousie University in Nova Scotia, presented the findings at the 2020 virtual Liver Meeting of the American Association for the Study of Liver Diseases (poster 0742).
In total 1,441 adults completed the double-blind trial, in which 723 (454 women) received Engerix-B and 718 (436 women) received Sci-B-Vac. Of those who received Engerix-B, 60 had diabetes, as did 54 people who received Sci-B-Vac. Each group also had similar numbers of overweight people, smokers and regular alcohol users.
Both groups received three doses of their respective vaccine, at zero, four and 24 weeks. Investigators determined the seroprotection afforded by each vaccine—as measured by the percentage of participants whose anti–hepatitis B titers were at least 10 mIU/mL—at four weeks after the third vaccination, or day 196. They wanted to see if Sci-B-Vac offered noninferior protection in all participants aged 18 years and older, and superior protection for anyone who was at least 45.
Sci-B-Vac outperformed Engerix-B in every age group, in every region, in men and women, and in people with every comorbidity measured, Langley and her colleagues reported. In all cases, the triple-antigen formulation yielded greater levels of seroprotection. The researchers hypothesized that these differentials were more pronounced in older age groups. For example, there was an 8.1% difference (95% CI, 3.4%-14.2%) in seroprotection among volunteers aged 18 to 44 years, and a 21.7% difference (95% CI, 9.7%-33.2%) in people aged 70 and older.
Compared with the Engerix-B vaccine, Sci-B-Vac was associated with more reactions at the injection site and higher levels of tenderness and myalgia. Investigators reported no safety signals.
“These findings are very promising,” said Freddy Caldera, DO, a gastroenterologist and an associate professor at the University of Wisconsin School of Medicine and Public Health, in Madison, who added that the new vaccine could supplement or potentially replace Engerix-B. Caldera noted a head-to-head comparison of the triple-dose Sci-B-Vac and the two-dose HEPLISAV-B vaccine would be worthwhile.
—Marcus A. Banks
This article is from the May 2021 print issue.