Sensitive assays for hepatitis A antibodies.

Two commercial assay kits for detecting antibody to hepatitis A virus (anti-HAV) have been modified in order to increase their sensitivity. These modifications are made by less dilution of the test serum, in the case of Abbott HAVAB-M assay, or by an increase in the volumetric ratio of the test serum to the labeled anti-HAV in the case of the Abbott HAVAB assay. These modifications result in 5- to 20-fold increases in test sensitivity and enable the detection of anti-HAV at 2-3 weeks following vaccination. The earlier detection of anti-HAV is important to vaccine development in assuring the presence of antibody levels in travelers sooner after vaccination.