What antibody titers should be ordered for immunization checks, including MMR (Measles, Mumps, Rubella), varicella, and hepatitis B?

Antibody Titers for Immunization Checks

Order measles IgG, mumps IgG, rubella IgG, varicella IgG, and hepatitis B surface antibody (anti-HBs) to assess immunity status when vaccination records are uncertain or unavailable. 1

MMR (Measles, Mumps, Rubella) Immunity Testing

• Measles IgG antibody: Order this serologic test to determine immunity when vaccination history is uncertain 1
• Mumps IgG antibody: Test for mumps immunity, particularly important for healthcare workers where documented immunity is "highly desirable" and increasingly required 2
• Rubella IgG antibody: Serologic testing for rubella IgG is widely available and should be included in the immunity assessment 1
• Interpretation: Antibody levels below the positive cutoff indicate susceptibility and lack of immunity, requiring vaccination 2

Alternative Approach for MMR

• Revaccination with MMR is an acceptable alternative to serologic testing, as it is safe even in those already immune and avoids the need for laboratory interpretation 1
• No evidence indicates that administering MMR vaccine increases the risk for adverse reactions among persons who are already immune from previous vaccination or natural disease 1

Varicella Immunity Testing

• Varicella IgG antibody (VZV IgG): Order by ELISA to determine immunity status 1
• Clinical correlation: History of varicella disease has a positive predictive value of 99.3% when correlated with VZV IgG antibody detection 3
• Alternative approach: Age-appropriate vaccination of persons who lack evidence of varicella immunity is recommended rather than routine serologic testing if vaccination history is adequate 1

Hepatitis B Immunity Testing

• Hepatitis B surface antibody (anti-HBs): This is the critical test to order for determining hepatitis B immunity 1
• Protective threshold: Anti-HBs levels ≥10 mIU/mL indicate seroprotection and clinical protection against hepatitis B infection 1
• Non-protective levels: Antibody levels <10 mIU/mL are considered non-protective, indicating either non-vaccination or non-response to prior vaccination 2

Additional Hepatitis B Testing

• Hepatitis B surface antigen (HBsAg): Should be tested before vaccinating to rule out active infection, particularly in foreign-born persons from endemic regions 1
• Important caveat: Blood should be drawn to test for HBsAg before vaccinating, as hepatitis B vaccine can give a false-positive HBsAg result up to 18 days after vaccination 1

Post-Vaccination Antibody Testing

Hepatitis B Post-Vaccination Testing

• Timing: Perform anti-HBs testing 1-2 months (or 4-8 weeks) after completing the vaccine series to document response 1, 2
• Challenge dose protocol: For patients who previously completed a full series but are not seroprotected (anti-HBs <10 mIU/mL), administer a single challenge dose and measure anti-HBs 4-8 weeks later to evaluate for an amnestic response 1
• Amnestic response: An anti-HBs level ≥10 mIU/mL after the challenge dose indicates immunologic memory, and no further doses are needed 1
• Non-responders: If no amnestic response occurs, complete a second full 2- or 3-dose series 1

MMR and Varicella Post-Vaccination Testing

• Not routinely recommended: Serologic testing after MMR or varicella vaccination is not recommended with appropriate immunization history 1
• Exception: Post-vaccination testing may be considered in specific circumstances such as healthcare workers or immunocompromised individuals 2

Common Pitfalls and Caveats

• Timing interference: Immune globulin products can interfere with antibody responses to measles and rubella vaccines for varying durations depending on the dose administered 1, 4
• Non-responders to hepatitis B: Approximately 5-15% of immunocompetent adults fail to respond to the initial hepatitis B vaccine series and require counseling about HBIG prophylaxis after any HBsAg-positive exposure 2
• Healthcare worker requirements: Healthcare workers born in 1957 or later require documented immunity or two doses of MMR, and any healthcare worker with blood exposure risk requires hepatitis B vaccination 2
• Documentation: Record all vaccination dates and serologic test results in the patient's permanent medical record, ensuring this documentation is readily accessible for occupational health purposes 2

Tests NOT Routinely Ordered

• Tetanus and diphtheria antibodies: Serologic testing for specific IgG antibody to tetanus and diphtheria toxins is only recommended in specific circumstances, such as after a severe local reaction or for persons with ≥3 documented doses 1
• Other vaccines: Serologic testing is not routinely available or recommended for vaccines such as Hib, pneumococcal, HPV, or rotavirus 1