Children undergoing chemotherapy are immunocompromised and may experience more severe flu episodes. Flu infections in these patients can lead to hospital admissions and delays in chemotherapy.

• Flu vaccination can help reduce illness, hospitalisation, and school absences.
• Timing of vaccination is vital, as delays may result in missed opportunities for immunisation.
• Missed vaccinations should be followed up.

Who should be vaccinated?

• Children currently or within six months of completing chemotherapy.
• Immediate family members/household. 

Timing of vaccination

• Ideal before the end of November.
• When not neutropenic (neutrophils > 0.5 × 10⁹/L).
• Leukaemia patients: best during maintenance treatment.
• Children on Vincristine/Dexamethasone pulses: best during mid-way between pulse.
• Solid tumour patients: after full blood count recovery and just before the next chemo cycle.

Vaccine type

• Quadrivalent Inactivated flu vaccine (injectable) is recommended for 
  • children on treatment for leukaemia or solid tumours
  • children within three months of completing treatment.
• Live attenuated vaccine (nasal spray, Fluenz®) 
  • can be given after three months post-treatment
  • not licensed for children under two years
  • safe for siblings aged two and over.

Dosage (by age and history)

• Children six months to <nine years
  • never vaccinated before: two doses, four weeks apart
  • previously vaccinated: one dose
• Children ≥nine years 
  • one dose.

Special cases

• Children on targeted therapies (e.g. Larotrectinib, Dabrafenib, Trametinib) and no chemo in the last three months, can receive live nasal vaccine.
• Children three to six months post-treatment and under two years require an inactivated vaccine.

Siblings/household contacts

• Safe for siblings to receive live nasal vaccine (no isolation from immunocompromised child needed).
• Vaccinating household enhances protection for the child.