Hepatitis B Seroconversion Rate After Primary Immunization Series with Newly Introduced Pentavalent Vaccine: A Report of Local Study in Alborz Province, Iran, 2016

Background: Since November 2014, pentavalent vaccine is available in Iran. This vaccine should be injected into all Iranian children at two, four, and six months after birth. Objectives: There is little information on the immunogenicity of this vaccine against hepatitis B (HB) in Iranian children; therefore, the current study aimed at investigating the vaccine efficacy six months after administration of the last dose. Methods: A total of 400 blood samples were collected from one-year-old children referred to Karaj healthcare centers, Alborz province, Iran. After sampling, checklists of demographic information were completed. Blood samples were sent to the laboratory to determine antibody titer by CMIA (chemiluminescent microparticle immunoassay). Statistical analysis was conducted by Stata and SVY software. Results: Overall, 393 (98.3%) children (95% confidence interval (CI): 96.03% - 99.57%) had a protective IgG titer of > 10 mIU/mL, while it was < 10 mIU/mL in seven (95% CI: 0.5% - 3.1%) subjects. Geometricmeantiter was 419.66 mIU/mL (95% CI: 380.52 - 462.82). Anti-HBsAb titer was not associated with gender and the type of milk feeding. Conclusions: The seroprotection of HB vaccine in a pentavalent combination vaccine in Iran, six months after three doses of vaccination, was acceptable.