Mono (Epstein-Barr Virus) Antibody Test

A positive result means certain EBV antibodies were detected in your sample. Depending on which antibodies are present, results may suggest past exposure or a more recent immune response pattern. Because most adults have been exposed to EBV at some point, positive findings are common and are best discussed with a healthcare professional who can interpret the full antibody profile.^1,2

Some people do not experience any noticeable symptoms. When symptoms do occur, they may include:

• Fatigue
• Sore throat
• Fever
• Swollen lymph nodes
• General feelings of illness

These symptoms can overlap with many other common conditions, which is why laboratory testing may be used as one part of a broader evaluation.^1,3

This test detects several antibodies your immune system may produce in response to Epstein-Barr virus (EBV). The meaning of your results depends on the combination of antibodies detected. Because EBV antibodies can remain in the body long after an infection, results may reflect recent or past exposure.

Your results are interpreted by looking at which EBV antibodies are positive, not simply how high the numbers are. This test measures three antibodies that appear at different points after exposure:

• VCA IgM and IgG positive, with EBNA IgG negative: This pattern is associated with a new or recent EBV infection.
• VCA IgG and EBNA IgG positive: This pattern is associated with a past EBV infection.
• All three antibodies negative: This usually means no EBV antibodies were detected, which may indicate that you have not previously been exposed.
• VCA IgM positive by itself: The timing may be unclear, and the report may include an interpretation or recommend reviewing the result with a healthcare professional.

The number shown above the positive cutoff does not indicate how severe or active an infection is. EBV antibodies can remain detectable long after an infection, so a “high” value does not necessarily mean that EBV is causing current symptoms. A healthcare professional can interpret the full antibody pattern together with your symptoms, health history, and other test results.²

Epstein-Barr virus (EBV) is very common. According to the CDC, most people are infected with EBV at some point in their lives, often during childhood. About 9 out of 10 adults have antibodies showing current or past infection. A positive EBV antibody result is common and does not necessarily mean you have an active illness.¹

EBV antibody tests may not detect an infection immediately after exposure because your immune system needs time to produce measurable antibodies. VCA IgM appears early in an EBV infection, while VCA IgG develops during the early stage and typically peaks two to four weeks after symptoms begin and persists for life. EBNA IgG usually appears later, about two to four months after symptoms start, and persists for life. Because the timing can vary, a healthcare professional may recommend repeat testing if your results are negative, but a recent infection is still suspected.⁴

Your testing will be performed in a CLIA-certified clinical laboratory. Labcorp provides leading-edge medical laboratory tests and services through a national network of primary clinical laboratories and specialty testing laboratories. Our labs perform regular quality assurance testing to ensure our results are accurate.

Your results will be provided to you through our secure online portal to view or print. Results are also made available through a secure portal to the independent healthcare provider who placed your test order.  If you are accessing your results through your Labcorp Patient™ account, all users linked to the account will have access to all OnDemand test results. Results may also be provided to a local, state, and/or federal health authority; for example, many states require the testing laboratory and physician to report test results for certain communicable diseases, such as COVID-19, to local or state health departments.  

If you have questions or comments regarding the Labcorp Notice of Privacy Practices, or have a complaint about our use or disclosure of your PHI or our privacy practices, please contact: privacyofficer@labcorp.com, call us at (877) 234-4722 (877-23-HIPAA) and ask for the Labcorp HIPAA Privacy Officer, or send a written request to: HIPAA Privacy Officer, Labcorp, 531 South Spring Street, Burlington, NC 27215. You also may file a complaint with the Secretary of the U.S. Department of Health and Human Services.

Visit the Labcorp OnDemand® website to browse and purchase laboratory tests and create your Labcorp Patient™ account to view your results. All Labcorp OnDemand testing requires an order from an authorized healthcare professional. For your convenience, Labcorp OnDemand has contracted with independent professional entities (collectively, Providers) to deliver healthcare provider services. Visit a Labcorp location for sample collection; or, if using an at-home collection kit, collect your sample yourself. We’ll let you know when your results are ready and can be accessed through your Labcorp Patient™ account.

To align with clinical best practices, we’ve set an age maximum of 100 for consumer-initiated testing. This limit was set to encourage individuals in more advanced age groups - who may have complex medical needs - to receive personalized guidance about testing from their healthcare providers.