Interchangeability and tolerability of two inactivated hepatitis A vaccines in Chinese children.

In China, no data are available to evaluate the interchangeability between Chinese domestic inactivated hepatitis A vaccines (Healive) and imported inactivated hepatitis A vaccines (Havrix). A double-blind, randomized controlled study was to compare interchangeability and safety of Healive and Havrix among Chinese children. Vaccine was administered to 303 healthy children at 0 and 6 months in one of four vaccine regimens: Healive-Healive; Healive-Havrix; Havrix-Healive or Havrix-Havrix. We collected sera samples at 0 (before vaccination), 6 (before second dose) and 7 months (after second dose), and compared groups in terms of proportion of sero-conversions which is defined as ≥ 20 mIU/ml, and geometric mean concentrations (GMCs) of anti-hepatitis A virus (HAV) antibody. Seroconversion rates were 133/133 (100%) for those received one dose of Healive and 105/131 (80.2%) for those received one dose of Havrix at 6 months, respectively (P<0.001), GMCs for Healive and Havrix were 126.1 and 40.9 mIU/ml (P<0.001), respectively. At 7 months, the seroconversion rate was 100% among all groups. The GMC after two doses of Healive was 8905.5 mIU/ml compared with 1900.9 mIU/ml after two doses of Havrix (P<0.001). The GMC in the Healive-Havrix group was 3275.8 mIU/ml compared with 4165.8 mIU/ml in the Havrix-Healive group (P=0.058). There is not different of reported adverse reactions across the groups. The present study indicated that both vaccines can be recommended for interchangeable using of immunization among Chinese healthy children.