EPSTEIN BARR VIRUS VIRAL CAPSID ANTIGEN IGG

Epstein-Barr Virus (EBV) Viral Capsid Antigen IgG

What it is

The EBV Viral Capsid Antigen (VCA) IgG test detects IgG antibodies directed against the viral capsid proteins of Epstein-Barr Virus (EBV). EBV is a herpesvirus responsible for infectious mononucleosis and is associated with several chronic conditions and cancers. VCA IgG antibodies appear during the acute phase of infection and persist for life, making them a reliable marker of past EBV exposure and long-term immunity.

Uses

This test is used to confirm whether a person has ever been infected with EBV. When interpreted with other EBV markers (VCA IgM, EBNA IgG, EA IgG), it helps differentiate acute, past, or reactivated infections. It is often ordered when investigating prolonged fever, fatigue, swollen lymph nodes, or suspected mononucleosis, and is also important in immune status assessments for transplant patients or immunocompromised individuals.

Symptoms That May Lead to the Test

Doctors may recommend this test if you have symptoms of EBV infection such as sore throat, prolonged fatigue, fever, swollen lymph nodes, rash, or an enlarged liver or spleen. It is also useful in distinguishing EBV from other causes of viral illness.

Abnormal Results

Positive VCA IgG: Indicates past or resolved EBV infection. Antibodies remain present for life and signify immunity against reinfection.

Negative VCA IgG: Suggests no prior EBV infection or immunity. In suspected acute infection, additional EBV antibody tests (VCA IgM, EBNA, EA) or PCR may be necessary.

Risks

The test requires a simple blood sample. Risks are minimal and limited to mild pain, bruising, or dizziness at the puncture site, which resolve quickly.