Source Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA.
BACKGROUND: A hepatitis B vaccine was manufactured with a modified process (mpHBV) that incorporated double the usual amount of phosphate. Following a study in young adults, the mpHBV was evaluated in infants in a combination hepatitis B and Haemophilus influenzae B vaccine (mpHBV-Hib).
METHODS: The mpHBV-Hib was compared with the licensed bivalent HBV-Hib vaccine Comvax™ for immunogenicity and safety. Both vaccines contained 5μg/0.5mL of hepatitis B surface antigen (HBsAg) and 7.5μg/0.5mL of PRP-OMPC (polyribosylribitol phosphate outer membrane protein complex). A total of 543 infants were randomized 1:1 to receive either vaccine at 2, 4 and 12 months of age. A pneumococcal conjugate vaccine (PCV) was given concomitantly. Immunogenicity was assessed at 1-month post-dose 3
RESULTS: Seroprotection rates [% subjects with anti-hepatitis B surface antigen antibody titers (anti-HBs) ≥10mIU/mL)] were 100% and 99% for mpHBV-Hib and the licensed control (Comvax™), respectively. Anti-HBs geometric mean titers (GMTs) were 4204 (95% CI, 3411-5182) and 1683 (95% CI, 1350-2099)mIU/mL, respectively. Anti-PRP seroprotection rates (SPR) at ≥0.15μg/mL and at ≥1.0μg/mL were 97% and 94%, respectively, for mpHBV-Hib and 96% and 92%, respectively, for the control. Anti-PRP GMTs were 7.1μg/mL for mpHBV-Hib and 8.0μg/mL for the control. Reactogenicity of the two vaccines was similar.
CONCLUSIONS: The mpHBV in combination with Hib and with co-administered PCV was highly immunogenic. The safety profile of mpHBV-Hib was comparable to the licensed control. Both the control and mpHBV-Hib met acceptability criteria for seroprotection rates to hepatitis B, with higher anti-HBs GMTs noted for mpHBV-Hib.