Effectiveness of Two Hepatitis B Vaccines in HIV-negative Youths

Hepatitis B Vaccination in Youth at Adolescent Trial Network Sites: Effectiveness of Two Strategies and Evaluation of Tools To be Used in Future HIV Prevention Trials.

This study will evaluate 2 licensed vaccine products (Recombivax and Twinrix) given in a two-dose schedule to youth at risk for hepatitis B and HIV infection to evaluate immunogenicity of the products in this population, barriers to vaccine delivery, and factors which predict a diminished immune response. Since these youths are also potential candidates for future HIV vaccine trials, this study will also include preliminary assessment of youths' understanding of informed consent forms, and willingness to participate in a vaccine trial and return for multiple visits (including blood draws for immunologic assessment).

Hepatitis B (HBV) prophylactic immunization has been recommended for at-risk adolescents for more than 10 years although universal coverage has not been achieved. Vaccine response in healthy adolescents has generally been reported to be excellent. But, data from the study Reaching for Excellence in Adolescent Care and Health (REACH) that studied HIV-negative adolescents who were at-risk of acquiring Hepatitis B infection through sexual or needle sharing behaviors has demonstrated a much lower than expected vaccine response rate in this population using standard vaccine dosing. Some data suggest that factors such as gender or body mass index might be responsible for the differences in response to the vaccine observed in individuals. The reason for the diminished vaccine response in this population is unclear. If in fact, Hepatitis B vaccine response is diminished in this population, then efforts to determine correlates of response and to improve the response are warranted. The proposed trial will evaluate 2 licensed vaccine products given in a two-dose schedule in youth at risk for hepatitis B and HIV infection to evaluate immunogenicity of the products in this population, barriers to vaccine delivery, and factors which predict a diminished immune response.

Since these youths are also potential candidates for future HIV vaccine trials, participation in such trials will require ability to understand and willingness to volunteer for such trials, ability to return for multiple vaccinations and blood draws to assess vaccine response, and willingness to participate in HIV prevention education. A hepatitis B vaccine trial will provide a licensed vaccine to youth in whom the vaccine is indicated and will allow preliminary assessment of youth's willingness to participate in a vaccine trial that involves blood draws for immunologic assessment.

Tools that will be necessary for HIV vaccine trials in youth include a youth-friendly simplified vaccine trial education component with a required written test for the participant, a standardized risk reduction education program, and a computer-assisted assessment of youth behaviors. These tools can be finalized and field tested in youth participating in the hepatitis B vaccine trial without promoting a false sense of protection from HIV. Secondary objectives of this trial will include assessment of a number of ancillary tools crucial for future HIV vaccine trials. This Hepatitis B vaccine trial will also serve as a HIV vaccine preparedness trial for youth at risk for both Hepatitis B and HIV.

Design: This is a phase II, randomized, single-blinded trial of two hepatitis B immunization regimens in 150 HIV-negative, hepatitis B core antibody, hepatitis B surface antigen and surface antibody negative youth. Vaccinations will be given in a two-dose regimen at 0 and six months (75 subjects in each arm) and the primary outcome will be seroresponsiveness one month after the 6-month dose. Safety and tolerability will also be assessed.

Inclusion Criteria:

• HIV negative youth age 12-17 years (No serologic evidence of HIV infection).
• Negative hepatitis B serology. (No serologic evidence of hepatitis B surface antigen (HBSAg), hepatitis B surface antibody (HBsAb or anti-HBs) and hepatitis B core antibody (HBcAb or anti-HBc)).
• Either no prior hepatitis B immunizations or unknown or incomplete hepatitis B immunization status.
• Willing to participate in HIV risk-reduction counseling and computer assisted measurement of behaviors.
• Parent or legal guardian willing to provide written permission
• Females of childbearing potential must have a negative pregnancy test at screening and should agree to avoid pregnancy through the end of the vaccine phase of the study. Females who are engaging in sexual intercourse must be willing to practice a reliable method of birth control through the end of the vaccine-phase of the study (approximately 6 months). The decision of what is "reliable" is at the discretion of the site investigator.

Exclusion Criteria:

• Presence of any serious illness requiring treatment with systemic medications, excluding treatment for asthma.
• Previous allergic reaction to any vaccines or to constituents of these vaccines (yeast, thimerosal or aluminum)
• Pregnancy
• Current immunomodulator therapy
• Receipt of immunosuppressor therapy (more than 10 mg/day of prednisone or equivalent for >1 week) in the 6 months preceding entry or anticipated long-term corticosteroid therapy in the above dose and duration. Short term (< 7 days) steroid use for the treatment of asthma is not an exclusion.
• Receipt of any vaccine within 2 weeks preceding study entry.