What is the recommended approach for a patient of any age in need of a flu shot and TB (tuberculosis) testing, considering their individual risk factors and medical history?

Flu Shot and TB Testing: Recommended Approach

Administer the influenza vaccine and tuberculin skin test (TST) or interferon-gamma release assay (IGRA) simultaneously on the same day, or proceed with either test without delay, as there is no clinically significant interaction between influenza vaccination and TB testing. 1, 2

Key Principle: No Interference Between Tests

• Influenza vaccination does not interfere with tuberculin skin testing or IGRA results, and TB testing does not affect vaccine immunogenicity. 1
• Both can be administered during the same clinical encounter without compromising the accuracy of either procedure. 1
• If same-day administration is not feasible, proceed with whichever is available first—there is no required waiting period between these interventions. 1

Influenza Vaccination Recommendations

Universal Recommendation

• Annual influenza vaccination is recommended for all persons aged ≥6 months without contraindications, regardless of TB testing status or results. 2, 3
• Vaccination should ideally occur in September or October but should continue throughout the influenza season as long as vaccine is available. 2

Priority Populations (Higher Risk)

• Children aged 6-59 months 2
• Adults aged ≥50 years (with preferential use of high-dose, recombinant, or adjuvanted formulations for those ≥65 years) 2, 3
• Pregnant women (any trimester) 4, 3
• Persons with chronic medical conditions (pulmonary, cardiovascular, metabolic diseases, immunosuppression) 4
• Healthcare workers and household contacts of high-risk individuals 4, 1

Contraindications to Note

• Anaphylactic hypersensitivity to vaccine components is an absolute contraindication. 1, 2
• Live attenuated influenza vaccine (LAIV/FluMist) is contraindicated in pregnancy, immunocompromised persons, and adults ≥50 years—use inactivated vaccine instead. 1, 5
• Moderate to severe acute illness warrants deferral until recovery, but minor illnesses do not. 1

TB Testing Considerations

When to Perform TB Testing

• TB testing should be performed based on individual risk factors: recent exposure to active TB, immigration from high-prevalence countries, healthcare occupation, immunosuppression, or residence in congregate settings. 1
• Either TST (tuberculin skin test) or IGRA (interferon-gamma release assay) can be used; IGRA is preferred in BCG-vaccinated individuals to avoid false positives. 1

Timing Relative to Vaccination

• No waiting period is required between influenza vaccination and TB testing in either direction. 1
• Unlike live viral vaccines (MMR, varicella), which can theoretically suppress TST reactivity if TST is not placed on the same day, inactivated influenza vaccine does not cause this issue. 1

Practical Clinical Algorithm

1. Assess contraindications to influenza vaccine (anaphylaxis history, current moderate/severe illness). 1
2. Administer influenza vaccine using age-appropriate formulation (inactivated for all ages ≥6 months; high-dose/adjuvanted/recombinant preferred for ≥65 years). 2, 3
3. Simultaneously place TST or draw blood for IGRA if TB testing is indicated based on risk assessment. 1
4. Schedule TST reading in 48-72 hours if TST was used; IGRA results typically available within 24-48 hours. 1

Common Pitfalls to Avoid

• Do not delay influenza vaccination while waiting for TB test results—there is no medical reason to do so. 1, 2
• Do not withhold vaccines for minor illnesses (mild upper respiratory symptoms, low-grade fever without systemic illness)—only moderate or severe acute illness warrants deferral. 1
• Do not assume immunocompromised patients cannot receive influenza vaccine—inactivated influenza vaccine is safe and strongly indicated in this population, though live attenuated vaccine is contraindicated. 1, 5
• Do not use live attenuated influenza vaccine (FluMist) in pregnant women, immunocompromised patients, or adults ≥50 years—always use inactivated formulations in these groups. 1, 5

Special Populations

Immunocompromised Patients

• Inactivated influenza vaccine is safe and recommended annually. 1, 5
• IGRA may be preferred over TST for TB screening due to better specificity and no need for return visit. 1

Pregnant Women

• Inactivated influenza vaccine is recommended during any trimester. 4, 3
• TB testing can proceed without concern for vaccine interference. 1

Healthcare Workers

• Annual influenza vaccination is strongly recommended to protect both workers and patients. 4, 1
• TB testing is typically required at baseline and periodically based on occupational exposure risk. 1