FluMist Vaccine
FluMist
Generic Name
FluMist
Mechanism
- Live attenuated strains (A/H1N1, A/H3N2, B/Yamagata, B/Victoria) replicate at the nasal mucosa without causing disease.
- Induces neutralizing IgA and cell‑mediated immunity (CD4⁺ & CD8⁺ T cells).
- Provides rapid, cross‑protective immunity after a single dose.
Pharmacokinetics
| Parameter | Data |
| Absorption | Localized mucosal uptake; minimal systemic circulation. |
| Distribution | Primarily confined to nasopharyngeal tissues; limited systemic spread. |
| Metabolism | Virus replication leads to spontaneous clearance; cellular degradation. |
| Excretion | Replicating virus cleared via mucociliary clearance and immune mechanisms. |
> *Because of its local action, pharmacokinetic profiling is largely unnecessary for therapeutic monitoring.*
Indications
- Prevention of seasonal influenza in:
- Children aged 2–49 months (first dose) or 2 – 18 years (subsequent doses).
- Adults > 2 years (only when no contraindications).
- Annual immunization prior to the influenza season.
Contraindications
| Contraindication | Reason |
| **Use 20 mg/day) | Risk of uncontrolled viral replication. |
| Asthma or reactive airway disease | May worsen bronchospasm. |
| History of vaccine‑related severe hypersensitivity (anaphylaxis) | Avoid all vaccines containing the same allergen. |
| Congenital defects of the upper respiratory tract | May impede delivery and increase infection risk. |
Dosing
- Dosage: *1 dose* (0.1 mL/nostril; 0.2 mL total).
- Age‑specific dosing:
- 12–23 months: 1 dose; 2‑4 weeks later, a second dose for full protection.
- 24 months‑< 2 years: 1 dose; 2‑3 weeks later, a second dose.
- ≥ 5 years: 1 dose; no booster needed.
- Administration: *Intranasal spray* (no needle), delivered in a single session.
- Timing: Administer at least 2 weeks before influenza activity peaks.
Adverse Effects
| Category | Examples |
| Common (≤ 5 %) | Nasal congestion, runny nose, sore throat, mild fever, sore throat. |
| Less common (≤ 1 %) | Headache, dizziness, rash. |
| Serious (≤ 0.01 %) | Asthma exacerbation, wheezing, anaphylaxis, persistent fever > 7 days, severe nasal bleeding. |
> *Most adverse events are self‑limited and resolve without intervention.*
Monitoring
- Pre‑vaccination:
- Allergy history, asthma control, immune status.
- Post‑vaccination (days 1–7):
- Monitor temperature, respiratory symptoms, and mucociliary clearance.
- Follow‑up (if symptomatic):
- Assess for asthma aggravation; consider bronchodilator therapy if needed.
- If severe reaction: initiate emergency management (epinephrine, steroids, antihistamines).
Clinical Pearls
- Yearly updates: Vaccine strains change annually; ensure the current strain mix is used.
- Live vs. inactivated: FluMist induces mucosal IgA; may be superior in children but less effective in adults over 50.
- Contraindications often omitted: Remember asthhma and immunocompromise as key exclusions—exceedingly important for clinical decision‑making.
- Booster strategy: Children 12–23 months *must* receive two doses; skipping the second dose halves protection.
- Storage: Keep 2–8 °C; avoid freezing. Once thawed, use within 24 h.
- Administration technique: Tilt patient’s head back; spray alternately in each nostril to ensure even delivery.
- Patient counseling: Emphasize the importance of early administration; too close to the influenza season reduces effectiveness.
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• Key terms highlighted on first mention make this card ideal for quick review by medical students and practice clinicians seeking a concise, evidence‑based refresher.