Safety and immunogenicity of a combined hepatitis B virus-Haemophilus influenzae type B vaccine formulation in healthy adults.

We administered a combined preparation of hepatitis B virus (HBV) vaccine and Haemophilus influenzae type b (Hib) conjugate vaccine (meningococcal protein conjugate) to 20 healthy adult volunteers. Participants received two doses of vaccine one month apart, and had serum samples drawn each time they received the vaccine and 1 month after the second dose. In 18 of 19 persons who were positive for antibody to hepatitis B surface antigen (anti-HBs), these levels had a median fold increase of 23.4 (range 0.69 to 270) 1 month after the first dose of vaccine. Anti-HBs levels generally fell slightly one month after the second dose was given. All of the study participants initially had detectable levels of antibody to Hib capsular polysaccharide (anti-PRP), and 19 of the 20 exhibited a median fold increase of 11.2 (range 0.81 to 740) in anti-PRP 1 month after vaccination. Over half (65%) continued to demonstrate increased levels of anti-PRP with the second dose of vaccine. Most participants experienced some slight to moderate discomfort at the injection site. The results indicate that the combined Hib/HBV vaccine produces increased antibody levels in healthy adults who have previously been exposed to these two antigens.