Can patients undergoing chemotherapy for multiple myeloma receive the influenza (flu) vaccine?

Influenza Vaccination for Multiple Myeloma Patients Undergoing Chemotherapy

Patients with multiple myeloma undergoing chemotherapy should receive the inactivated influenza vaccine, as it is safe and can provide protective immunity despite potentially reduced response rates compared to healthy individuals. 1

Rationale and Efficacy

Multiple myeloma patients have compromised immune systems due to both the disease itself and chemotherapy treatments, making them particularly vulnerable to infections including influenza. The European Myeloma Network and other authoritative guidelines strongly recommend influenza vaccination for these patients.

• Clinical studies show seroconversion after influenza vaccination in approximately 70-80% of patients with malignancies 1
• A Cochrane review of 2275 cancer patients revealed a significant reduction in mortality among those receiving influenza vaccines 1
• While response rates may be lower in multiple myeloma patients compared to healthy individuals, a substantial portion still achieve protective antibody titers 1

Timing Considerations

The timing of vaccination relative to chemotherapy cycles can affect immune response:

• For multiple myeloma patients, vaccination is ideally administered:

  • Before starting treatment when possible 1
  • When leukocyte count is normal 1
  • Just before initiation of a chemotherapy cycle 1
  • At the furthest possible time point away from treatment during a given cycle 1

• Studies suggest that patients who have completed treatment show superior responses compared to those still receiving treatment 1

Dosing Strategy

Standard influenza vaccination may not provide optimal protection for multiple myeloma patients:

• A two-dose strategy may be more effective than a single dose 1, 2
• Rates of seroprotection against all three influenza strains increased from baseline 4% to 49% after one dose and 65% after two doses in a study of plasma cell disorder patients 2
• Consider administering two doses within a 4-week interval for patients without documented immune response 1

Special Considerations

Response to vaccination may vary based on treatment regimen:

• Patients on immunomodulatory drugs alone or with proteasome inhibitors may have better serologic responses 2
• Patients on rituximab may have particularly impaired responses due to B-cell depletion 1
• Active conventional chemotherapy may reduce likelihood of response 2

Safety

• Inactivated influenza vaccines are safe for patients undergoing chemotherapy 1
• Live attenuated influenza vaccines should be avoided in patients receiving chemotherapy 1
• Family members and caregivers of multiple myeloma patients should also be vaccinated to provide "cocoon immunity" 1

Clinical Impact

Recent evidence suggests vaccination may improve outcomes:

• A 2023 global observational study found that influenza vaccination was associated with improved overall survival in multiple myeloma patients (HR 0.73,95% CI 0.60-0.90) 3
• The same study showed lower proportions of deaths due to infections among vaccinated patients compared to non-vaccinated patients 3

Common Pitfalls to Avoid

1. Skipping vaccination due to concerns about efficacy - even partial protection is valuable
2. Using live attenuated vaccines instead of inactivated vaccines
3. Not considering a two-dose strategy for optimal protection
4. Failing to vaccinate family members and caregivers
5. Not documenting vaccination status in medical records

Despite potentially reduced efficacy compared to healthy individuals, influenza vaccination remains an important preventive measure for multiple myeloma patients undergoing chemotherapy, with evidence suggesting it may improve survival outcomes.