CDC Guidelines for Flu Vaccination in Adults 65 Years and Older
Adults aged 65 years and older should preferentially receive one of three enhanced influenza vaccines: high-dose trivalent inactivated influenza vaccine (HD-IIV3), trivalent recombinant influenza vaccine (RIV3), or trivalent adjuvanted inactivated influenza vaccine (aIIV3). 1, 2
Preferred Vaccine Options for Adults ≥65 Years
The CDC's Advisory Committee on Immunization Practices (ACIP) specifically recommends that older adults receive one of these enhanced vaccine formulations due to their superior efficacy in this age group:
- High-dose trivalent vaccine (HD-IIV3) - Contains 60 μg of hemagglutinin per virus strain (4× the standard dose)
- Adjuvanted trivalent vaccine (aIIV3) - Contains MF59 adjuvant to enhance immune response
- Recombinant trivalent vaccine (RIV3) - Produced using recombinant technology
Evidence Supporting Enhanced Vaccines
The recommendation for enhanced vaccines is based on strong evidence showing superior protection compared to standard-dose vaccines:
- HD-IIV3 demonstrated 24.2% higher relative efficacy against laboratory-confirmed influenza compared to standard-dose vaccines in a large randomized trial with 31,989 participants aged ≥65 years 2
- In a randomized trial, HD-IIV3 met prespecified criteria for superior efficacy compared to standard-dose IIV3 1
- Enhanced vaccines help overcome the reduced immune response typically seen in older adults 2
- Real-world data shows that high-dose vaccination is associated with reduced risk of influenza infections, hospitalizations, and mortality in this age group 2
Timing of Vaccination
- Vaccination should ideally be administered before the onset of influenza activity in the community, preferably by the end of October 2
- Annual vaccination is recommended regardless of whether the vaccine composition has changed 1
Important Considerations
When Preferred Vaccines Are Not Available
If none of the preferred vaccines (HD-IIV3, aIIV3, or RIV3) is available at the time of vaccination, any age-appropriate standard-dose influenza vaccine should be used rather than delaying vaccination 1, 2. Vaccination should not be postponed to obtain a specific product when an appropriate alternative is available.
Safety Profile
- Enhanced vaccines have similar safety profiles to standard-dose vaccines 2
- Common side effects include more frequent injection site reactions and slightly higher rates of systemic reactions with high-dose formulations 2
- No significant increase in serious adverse events has been observed with enhanced vaccines compared to standard-dose vaccines 2
Special Populations
For solid organ transplant recipients aged 18-64 years who are receiving immunosuppressive medications, HD-IIV3 or aIIV3 are acceptable options (without preference over other age-appropriate IIV3s or RIV3) 1.
Vaccine Composition for 2024-25 Season
All influenza vaccines for the 2024-25 season will be trivalent, containing:
- An influenza A/H1N1 component
- An influenza A/H3N2 component
- An influenza B (Victoria lineage) component 1
Clinical Implications
The preferential recommendation for enhanced vaccines in adults ≥65 years is significant because:
- Older adults are at higher risk for influenza complications, hospitalizations, and death
- Residents of nursing homes and long-term care facilities may experience influenza attack rates as high as 60% with case-fatality ratios exceeding 30% 2
- Enhanced vaccines provide better protection against influenza-related outcomes in this vulnerable population
By following these CDC guidelines and prioritizing enhanced influenza vaccines for adults aged 65 years and older, healthcare providers can help reduce the burden of influenza in this high-risk population.