What is the recommended flu vaccine for elderly patients?

High-Dose Influenza Vaccine for Elderly Patients

The Advisory Committee on Immunization Practices (ACIP) recommends preferential use of high-dose or adjuvanted influenza vaccines for all adults aged 65 years and older. 1

Specific Vaccine Recommendation

• Fluzone High-Dose (HD-IIV4) is the recommended formulation for elderly patients ≥65 years, containing 60 μg of hemagglutinin per strain—four times the amount in standard-dose vaccines. 1
• This vaccine is FDA-licensed specifically and exclusively for adults aged 65 years and older. 1
• Administration is a single 0.5 mL intramuscular injection in the deltoid muscle, given once per influenza season. 1

Clinical Evidence Supporting This Recommendation

The evidence strongly favors high-dose vaccine in elderly populations:

• In a randomized trial of 31,989 persons aged ≥65 years, Fluzone High-Dose demonstrated superior efficacy with a relative efficacy of 24.2% (95% CI: 9.7%–36.5%) compared to standard-dose vaccine for preventing laboratory-confirmed influenza. 1
• High-dose vaccine reduces mortality risk by 48% and hospitalization risk by 27% in adults ≥65 years. 2
• Among nursing home residents >65 years, high-dose vaccine reduced respiratory-related hospital admissions (3.4% vs. 3.9%) and mortality (17.1% vs. 18.3%) compared to standard-dose. 1
• The effectiveness is most pronounced in adults aged ≥75 years, though benefits extend to all individuals ≥65 years regardless of comorbidities, frailty, or prior vaccination history. 1, 3

Age-Stratified Considerations

While high-dose is recommended for all ≥65 years:

• The greatest clinical benefit and cost-effectiveness occurs in adults ≥75 years. 1, 3
• Evidence supporting superiority over standard-dose in the 65-74 age group is less robust and often not statistically significant. 3
• However, ACIP maintains the preferential recommendation for all adults ≥65 years without age stratification. 1, 2

Special Populations Under Age 65

High-dose vaccine may be considered off-label for select immunocompromised patients <65 years:

• Solid organ transplant recipients aged 18-64 years receiving immunosuppressive medications. 1, 4
• Patients with rheumatic and musculoskeletal diseases aged >18 and <65 years taking immunosuppressive medication. 1, 4
• This use is off-label and may require insurance prior authorization. 4

Critical Implementation Points

• If high-dose vaccine is not available, administer standard-dose vaccine immediately rather than delaying vaccination—any influenza vaccine is superior to no vaccination. 1, 2
• Do not administer influenza vaccine in July or August to adults ≥65 years due to concerns about waning immunity before peak influenza season. 1
• High-dose vaccine is available as a prefilled syringe and should not be confused with standard-dose formulations. 1

Safety Profile

• High-dose vaccine recipients experience more frequent injection site reactions and systemic symptoms compared to standard-dose recipients, but the overall safety profile remains favorable. 1, 5
• The enhanced reactogenicity reflects the increased immune response and does not indicate a safety concern. 5, 6

Cost-Effectiveness

• High-dose vaccine is cost-effective in elderly populations, reducing healthcare costs by 2.75% and years of life lost by over 50%. 1, 2
• The benefit-to-cost ratio is most favorable in adults ≥75 years. 1
• Despite higher acquisition costs, the reduction in hospitalizations and mortality justifies preferential use. 6