Subjective Assessment Before Administering Quadrivalent Inactivated Influenza Vaccine
Before administering any quadrivalent inactivated influenza vaccine (IIV4), you must systematically screen for contraindications and precautions by asking about: (1) history of severe allergic reactions to previous influenza vaccines or vaccine components, (2) history of Guillain-Barré syndrome within 6 weeks of prior influenza vaccination, and (3) current moderate-to-severe acute illness. 1
Essential Screening Questions
1. Allergy History (Absolute Priority)
Ask specifically about:
- Previous severe allergic reaction (anaphylaxis) to ANY influenza vaccine - This is a contraindication to egg-based IIV4 1
- Severe allergic reaction to any vaccine component - Check package insert for specific components 1
- Egg allergy history - Note: This is NO LONGER a practical contraindication. ACIP recommends that persons with egg allergy may receive any age-appropriate influenza vaccine, though those with severe reactions (angioedema, respiratory distress, recurrent emesis, or requiring epinephrine) should be vaccinated in a medical setting supervised by a provider who can manage severe allergic reactions 1
Important caveat: If the patient had anaphylaxis to a previous influenza vaccine but the specific vaccine type is unknown, allergist consultation is recommended before proceeding 1
2. Guillain-Barré Syndrome (GBS) History
Ask: "Have you ever had Guillain-Barré syndrome? If yes, when did it occur in relation to any previous flu shot?"
- GBS within 6 weeks of prior influenza vaccination is a precaution (not absolute contraindication) 1
- Vaccination should generally be deferred, but may be given if benefits outweigh risks 1
- GBS occurring >6 weeks after vaccination or unrelated to vaccination is not a contraindication 2
3. Current Illness Status
Ask: "Are you currently sick with fever or moderate-to-severe illness?"
- Moderate or severe acute illness with or without fever is a precaution 1
- Defer vaccination until illness resolves
- Minor illnesses (mild upper respiratory infection) are NOT contraindications and vaccination can proceed
4. Medication History (For Live Vaccine Consideration)
While not directly relevant to IIV4, document:
- Recent influenza antiviral use (relevant if considering live attenuated vaccine as alternative) 3, 1
- In children/adolescents: aspirin or salicylate use (contraindication for LAIV, not IIV4) 1
Additional Context-Specific Questions
For Immunocompromised Patients:
- IIV4 can be safely administered to immunocompromised patients 2
- Document immunocompromising conditions for appropriate vaccine selection
For Pregnant/Lactating Women:
- IIV4 is safe and recommended during pregnancy and lactation 4
- No specific contraindications based on pregnancy status
Age-Appropriate Considerations:
- Confirm age to ensure appropriate vaccine formulation 1
- For children 6-35 months: verify if this is their first influenza vaccination season (affects dosing schedule - may need 2 doses) 1
Clinical Decision Algorithm
If YES to severe allergic reaction to previous influenza vaccine:
- STOP → Do not give same vaccine type
- Consider alternative vaccine type (ccIIV4 or RIV4) or allergist consultation 1
If YES to GBS within 6 weeks of prior flu vaccine:
- PAUSE → Assess individual risk-benefit
- Consider deferring unless patient is at very high risk for influenza complications 1
If YES to moderate/severe acute illness:
- DEFER → Reschedule when recovered 1
If NO to all above:
- PROCEED with vaccination 1
Common Pitfalls to Avoid
- Do not defer vaccination for egg allergy alone - This outdated practice prevents necessary immunization 1
- Do not confuse precautions with contraindications - Precautions mean "generally defer but may give if benefits outweigh risks," not "never give" 1
- Do not defer for minor illnesses - Mild upper respiratory infections without fever are not contraindications 1
- Do not assume all GBS history is a contraindication - Only GBS within 6 weeks of prior influenza vaccination is a precaution 2