A single dose of an inactivated hepatitis A virus (HAV) vaccine resulted in high seropositive rates and antibody concentrations, persisting for at least 5 years in children, a study has shown.

In October 2008, a team of investigators in China led by Zhilun Zhang of the Tianjin Center for Disease Control and Prevention, randomly assigned 332 children aged 18-60 months with prevaccination anti-HAV antibody titers of less than 20 mIU/mL to receive either one dose of inactivated hepatitis A vaccine or one dose of live, attenuated hepatitis A vaccine. Both groups were followed through December 2013, with assessments of anti-HAV antibody concentrations at years 1, 2, and 5 post vaccination. In all, 182 successfully completed the study, meeting all requirements, including providing serum samples at each time point.

At year 1, the rate was 95.3% in the group receiving the inactivated hepatitis A vaccine and 91.8% in the other group (P greater than .05). At year 2, the seropositive rate of the group receiving the inactivated vaccines was 90.6% and the rate for the group receiving the live, attenuated vaccine (P greater than .05) was 90.7%. At year 5, the seropositive rate was 85.9% for the group receiving the inactivated vaccine and 90.7% for the group receiving the live attenuated vaccine (P greater than .05).

Titer levels were 76.3% mIU/mL and 66.8mIU/mL for the inactivated and live vaccines at 5 years, respectively. No clinical hepatitis A case was reported.

The study appears online in Human Vaccines & Immunotherapeutics ( doi: 10.1080/21645515.2016.1278329 ).

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