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 the immune response to influenza vaccine. 1
• Both can be administered during the same clinical encounter without compromising the accuracy of either test or the effectiveness of vaccination. 1, 2
• If same-day administration is not feasible, proceed with whichever is available first—there is no required waiting period between these interventions. 1, 2

Universal Influenza Vaccination Recommendation

• Annual influenza vaccination is recommended for all persons aged ≥6 months without contraindications, making this a priority for virtually every patient presenting for care. 2, 3
• Vaccination should ideally occur in September or October, but should continue throughout the influenza season as long as vaccine is available. 2
• For adults ≥65 years, preferentially use enhanced formulations: high-dose inactivated (HD-IIV4), recombinant (RIV4), or adjuvanted (aIIV4) vaccines. 2

TB Testing Indications and Methods

While the evidence provided focuses primarily on influenza vaccination, TB testing should be performed based on:

• Risk factors including close contact with active TB cases, immunosuppression, healthcare work, or residence in high-prevalence areas
• Either TST (tuberculin skin test) or IGRA (interferon-gamma release assay) can be used, with IGRA preferred in BCG-vaccinated individuals to avoid false positives

Contraindications to Consider

For influenza vaccine:

• History of anaphylaxis to eggs or vaccine components requires physician consultation before administration. 2
• Live attenuated influenza vaccine (LAIV) is contraindicated in pregnancy, immunocompromised persons, and adults ≥50 years. 1, 2
• Moderate or severe acute illness warrants deferral until recovery. 1

For TB testing:

• Severe immunosuppression may cause false-negative TST results (IGRA is preferred in these patients)
• Recent live virus vaccination (MMR, varicella) may theoretically suppress TST response, but influenza vaccine (inactivated) does not cause this issue

Priority Populations for Influenza Vaccination

High-risk groups requiring prioritization include:

• Children aged 6-59 months and adults ≥50 years. 4, 2
• Pregnant women during any trimester. 4, 3
• Persons with chronic pulmonary, cardiovascular, metabolic, renal, or immunosuppressive conditions. 4, 2
• Healthcare workers and household contacts of high-risk individuals. 4, 2
• Residents of nursing homes and long-term care facilities. 4, 2

Common Pitfalls to Avoid

• Do not delay influenza vaccination while waiting to perform or read TB testing—there is no medical reason to separate these procedures. 1, 2
• Do not withhold influenza vaccine for minor illnesses—only moderate or severe acute illness warrants deferral. 1
• Do not assume that inactivated influenza vaccine will interfere with TST—this is a misconception; only live virus vaccines (MMR, varicella) may theoretically affect TST, and even this concern is minimal. 1
• Do not give LAIV to immunocompromised patients, pregnant women, or adults ≥50 years—use inactivated vaccine instead. 1, 2

Practical Implementation Algorithm

1. Assess contraindications to both influenza vaccine and TB testing (anaphylaxis history, severe acute illness, pregnancy status for LAIV). 1, 2
2. Administer influenza vaccine using age-appropriate formulation (enhanced vaccines for ≥65 years; inactivated for high-risk groups). 2
3. Perform TB testing simultaneously using TST or IGRA based on patient factors (IGRA preferred if BCG-vaccinated or immunocompromised).
4. Schedule TST reading for 48-72 hours if TST is used; IGRA results are typically available within 24-48 hours.
5. Document both interventions and ensure appropriate follow-up for TB test results. 1, 2