What test checks for immunity to Hepatitis A and Hepatitis B?

From the Guidelines

To check for immunity to Hepatitis A and Hepatitis B, blood tests that measure specific antibodies are used, specifically Hepatitis A antibody (anti-HAV) IgG for Hepatitis A and Hepatitis B surface antibody (anti-HBs or HBsAb) for Hepatitis B, as indicated by the most recent guidelines 1. These tests are crucial for determining immunity, which can be achieved through past infection or vaccination.

• For Hepatitis A, the presence of anti-HAV IgG indicates immunity, whether from past infection or vaccination.
• For Hepatitis B, the presence of anti-HBs (or HBsAb) indicates immunity from either vaccination or recovery from infection, as this antibody typically develops after the disappearance of the hepatitis B surface antigen (HBsAg) in individuals who have cleared the virus 1. The process involves simple blood draws that can be ordered by a healthcare provider.
• If the results show adequate antibody levels, an individual is considered immune and protected against future infection.
• If antibody levels are low or absent, vaccination may be recommended, especially for those at risk due to travel, occupation, or other factors, as outlined in prevention guidelines 1. These immunity tests are particularly important for certain groups, including:
• Healthcare workers
• Travelers to endemic regions
• Individuals with chronic liver conditions to ensure they have adequate protection against these viral infections, highlighting the importance of serologic testing in the management and prevention of hepatitis B virus infection 1.

From the Research

Tests for Immunity to Hepatitis A and B

To check for immunity to Hepatitis A and Hepatitis B, several tests can be used:

• For Hepatitis A, IgG anti-HAV indicates immunity from further infections of hepatitis A 2.
• For Hepatitis B, testing for hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) is considered the most efficient and reasonably cost-effective method to screen for hepatitis B serologic markers 3.
• Anti-HBs is indicative of recovery and immunity to Hepatitis B 2.
• Testing for antibodies to hepatitis B core antigen (anti-HBc) is needed to further distinguish between immunity due to vaccination and immunity due to past infection 3, 4.

Methods of Testing

These tests can be performed on various specimens, including:

• Blood serum 3, 2, 4, 5
• Urine specimens 6
• Saliva specimens 6

Interpretation of Results

The results of these tests can be used to:

• Identify patients who are already immune to Hepatitis A and B and do not need to be vaccinated 3
• Distinguish between immunity due to vaccination and immunity due to past infection 3, 4
• Diagnose acute or chronic Hepatitis B infection 2, 5