Does the Shingrix (zoster vaccine) vaccine affect Carcinoembryonic Antigen (CEA) test results?

Impact of Shingrix Vaccine on CEA Test Results

There is no evidence that the Shingrix (recombinant zoster vaccine) affects Carcinoembryonic Antigen (CEA) test results.

Background on CEA Testing

• CEA is a tumor marker primarily used for monitoring patients with colorectal cancer and some other malignancies, not as a screening test 1
• CEA elevations within one to two weeks following chemotherapy should be interpreted with caution due to potential spurious increases 1
• CEA is also used in monitoring metastatic breast cancer, though it is less commonly elevated than MUC-1 assays (CA 27.29 or CA 15-3) 1

Factors Known to Affect CEA Levels

• Chemotherapy administration can cause temporary CEA elevations that should be confirmed by retesting 1
• False elevations in CEA can occur in certain non-malignant conditions such as inflammatory bowel disease, pancreatitis, liver disease, and smoking 1
• No evidence in guidelines suggests that vaccines, including Shingrix, affect CEA levels 1

Shingrix Vaccine Information

• Shingrix is a non-live recombinant zoster vaccine administered as a two-dose series with doses given 2-6 months apart 2
• The vaccine contains varicella zoster virus glycoprotein E antigen and the AS01B adjuvant system 3
• Common side effects include injection-site reactions, myalgia, and fatigue, which are typically transient and mild to moderate in severity 2, 3

Immune Response to Shingrix

• Shingrix induces both humoral (antibody) and cell-mediated immune responses against varicella zoster virus 1
• Studies in immunocompromised patients, including those with hematological malignancies, show that Shingrix produces significant immune responses without affecting tumor markers 1, 4
• The immune response to Shingrix persists for at least 8 years with minimal waning 2

Clinical Considerations

• When monitoring cancer patients with CEA, any unexpected elevation should be confirmed by retesting before making treatment decisions 1
• If a patient has recently received Shingrix and shows an unexpected CEA elevation, consider retesting in 2-4 weeks to confirm the finding 1
• Unlike some medications or treatments, vaccines including Shingrix have not been documented to cause false elevations in tumor markers such as CEA 1

Special Populations

• For cancer patients undergoing CEA monitoring who also need Shingrix vaccination:
  • There are no contraindications or special timing considerations needed between CEA testing and Shingrix administration 1, 4
  • Shingrix is safe for use in immunocompromised patients, including those with malignancies 4, 3
  • The vaccine's efficacy in preventing herpes zoster in patients with inflammatory arthritis is approximately 50%, supporting its use in patients with various medical conditions 5

Pitfalls to Avoid

• Do not attribute CEA elevations to recent Shingrix vaccination without considering other more likely causes 1
• Remember that confirmed CEA elevations warrant further evaluation for metastatic disease, regardless of recent vaccinations 1
• When interpreting tumor marker results, always consider the clinical context and the patient's complete medical history 1