AIM: To investigate the immunogenicity of two versus three injections of inactivated strain CR326F-derived hepatitis A vaccine in healthy adults. METHODS:Healthy adult volunteers (n = 105) at Utrecht University Hospital, The Netherlands, were randomly assigned to receive intramuscular injections (deltoid muscle) of 25 Units (U) at 0 and 6 months (group A, n = 53), or at 0, 2 and 6 months (group B, n = 52). Blood was drawn before and at various time points after vaccination for determination of serum antibody to hepatitis A (anti-HAV). RESULTS: One month after the first injection, the seroconversion rates (> or = 10 mIU/ml, international units) were 88% for group A and 90% for group B. Only 2/ 103 (one in each group) showed IgM anti-HAV. One month after the second injection, seroconversion rates were 100% in both groups. At months 3, 6 and 7, anti-HAV geometric mean titers were significantly different because of the different vaccination schedules, but they were similar at months 1, 2 and 12. The anti-HAV geometric mean titer increase after the second injection was higher when the interval between the two doses was of longer duration. Anti-HAV titers of females were significantly higher than those of males and vaccinees < or = 30 years had higher titers than those > 30 years. CONCLUSIONS: Two 25 U doses of the vaccine investigated given at 0 and 6 months, induce adequate anti-HAV titers in all adult healthy vaccinees and are as immunogenic as three doses given at 0, 2 and 6 months.
RCT Entities:
AIM: To investigate the immunogenicity of two versus three injections of inactivated strain CR326F-derived hepatitis A vaccine in healthy adults. METHODS: Healthy adult volunteers (n = 105) at Utrecht University Hospital, The Netherlands, were randomly assigned to receive intramuscular injections (deltoid muscle) of 25 Units (U) at 0 and 6 months (group A, n = 53), or at 0, 2 and 6 months (group B, n = 52). Blood was drawn before and at various time points after vaccination for determination of serum antibody to hepatitis A (anti-HAV). RESULTS: One month after the first injection, the seroconversion rates (> or = 10 mIU/ml, international units) were 88% for group A and 90% for group B. Only 2/ 103 (one in each group) showed IgM anti-HAV. One month after the second injection, seroconversion rates were 100% in both groups. At months 3, 6 and 7, anti-HAV geometric mean titers were significantly different because of the different vaccination schedules, but they were similar at months 1, 2 and 12. The anti-HAV geometric mean titer increase after the second injection was higher when the interval between the two doses was of longer duration. Anti-HAV titers of females were significantly higher than those of males and vaccinees < or = 30 years had higher titers than those > 30 years. CONCLUSIONS: Two 25 U doses of the vaccine investigated given at 0 and 6 months, induce adequate anti-HAV titers in all adult healthy vaccinees and are as immunogenic as three doses given at 0, 2 and 6 months.
Authors: Caitlyn L Holmes; Chloe G Peyton; Amy M Bier; Tobias Z Donlon; Fauzia Osman; Christie M Bartels; Miriam A Shelef Journal: PLoS One Date: 2019-05-28 Impact factor: 3.240