Among 306 chronic hepatitis B infected (HBsAg+) individuals, 7.8% (24/306) were apparently unvaccinated and seronegative for hepatitis A. Among 3605 individuals whose status was consistent with vaccination (anti-HBs+, anti-HBc- and HBsAg-), 67.0% (2416) had had an annual anti-HBs measurement. The gene discussed is KRT88P; the disease is hepatitis A virus infection.