A three-dose course of the hepatitis-B vaccine Heplisav-B fully protected adults living with HIV who had never been vaccinated against or infected with the Hepatitis B Virus (HBV), according to study findings presented yesterday at the IDWeek conference in Washington, DC, a statement from the National Institutes of Health (NIH) has said.
The Heplisav-B vaccine, made by Dynavax Technologies based in Emeryville, California, was approved in 2017 by the US Food and Drug Administration (FDA) as a two-dose vaccine regimen for adults. However, little was known about its protective effects in people living with HIV, the statement noted.
Led by study chairs Kenneth E Sherman, MD, PhD, University of Cincinnati College of Medicine; and Kristen Marks, MD, Weill Cornell Medical College, New York City, the researchers tested a three-dose course of Heplisav-B among 68 adults living with HIV at 38 sites in the US, South Africa and Thailand. None of the participants had received a previous HBV vaccination or had evidence of a previous HBV infection; all were on anti-retroviral therapy. Following the initial dose of Heplisav-B vaccine 0.5 millilitre (mL) as an intra-muscular injection, study participants received additional doses at four weeks and 24 weeks. The objective of this part of the study was to assess anti-HBV surface antibodies (HBsAbs) greater than or equal to 10 milli-international units per millilitre (mIU/mL) at week 28 (defined as seroprotection from HBV) and to assess the vaccine’s safety, it further notified.
It also informed that all participants achieved seroprotection with 88 per cent of participants achieving HbsAb levels greater than 1000 mIU/mL, according to findings presented today. High antibody levels are thought to be associated with long-term vaccine durability. At eight weeks after the second dose, 94.4 per cent of participants achieved seroprotection; this percentage increased to 98.5 per cent by week 24 prior to the third dose. The most common side effects related to vaccination were injection site pain, malaise, fatigue, muscle aches and headaches.
The international study will continue to examine the effects of two-dose Heplisav-B, as well as a three-dose regimen of another hepatitis B vaccine (Engerix-B, manufactured by GSK) among adult participants with HIV who were previously vaccinated against HBV, but who did not achieve an adequate immunologic response. The clinical trial is estimated to complete vaccinations in March 2023, concluded the statement.