Time course of hepatitis A virus antibody titer after active and passive immunization

✍ Scribed by Shigetoshi Fujiyama; Shiro Iino; Koichi Odoh; Shoji Kuzuhara; Hiroaki Watanabe; Masahiko Tanaka; Kyosuke Mizuno; Tatsuo Sato

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 640 KB
• Volume: 15
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840150602

✦ Synopsis

To investigate the antibody titer necessary to prevent hepatitis A virus infection, either 15 or 7.5 mg/kg of immune serum globulin was injected into 10 antihepatitis A virus negative volunteers and their serum antihepatitis A virus titers were observed for 28 wk. In addition, antibody titers were observed for 96 wk in a phase 1 clinical trial of a hepatitis A vaccine.

The two studies were then compared to assess the immunogenicity of the vaccine and the persistence of the antibody. Serum-neutralizing antibody titers that were greater than or equal to 4 (considered as positive) persisted for 18 wk and 14 wk after the injection of 15 and 7.5 mg/kg of globulin, respectively. Hepatitis A virus vaccine recipients showed adequate neutralizing antibody titers, with the groups receiving 1, 0.5 and 0.25 pg/dose showing titers of 46*5, 44.7 and 44, respectively, at 18 mo after the third inoculation. These findings suggested that effective blood antibody titers were likely to be retained in the 1.0 kg or 0.5 Fg/dose groups for at least several years. Moreover, the serum antihepatitis A virus titers demonstrated by a modified radioimmunoassay changed in parallel with the neutralizing antibody titers in the volunteers injected with globulin. (HEPATOLOGY 1992; 15983-988.