As people age, their immune system, a process known as immunosenescence, naturally weakens. This reduced immune response can make older adults more vulnerable to influenza complications, such as pneumonia, hospitalization, and even death. For this reason, the Centers for Disease Control and Prevention (CDC) issues specific guidance for seniors.
Understanding the CDC's Preferential Recommendation
For the 2025–2026 flu season, the CDC and its Advisory Committee on Immunization Practices (ACIP) preferentially recommend higher-dose or adjuvanted flu vaccines for adults aged 65 and older. This means that while other age-appropriate vaccines are available, these enhanced formulations are considered better options for this population.
Studies have shown that these specialized vaccines can create a stronger immune response, leading to better protection against severe illness and hospitalization compared to standard-dose vaccines. However, the CDC does not express a preference among the three recommended enhanced options, and if none are available, a standard-dose vaccine should be administered.
A Breakdown of Preferred Flu Vaccines for Seniors (2025–2026)
High-Dose Vaccine (Fluzone High-Dose Quadrivalent)
This vaccine contains four times the amount of antigen—the component that triggers the immune response—compared to a standard-dose shot. The increased dose is designed to give the aging immune system a more potent stimulus. Clinical trials and real-world studies have shown it to be more effective than standard-dose vaccines for adults over 65.
Adjuvanted Vaccine (Fluad Quadrivalent)
Fluad uses a unique adjuvant, MF59, to create a more robust immune response. An adjuvant is an ingredient that helps boost the body’s response to the vaccine. This option is also designed for older adults and has been linked to a reduced risk of pneumonia and hospitalization compared to standard vaccines in some studies. Fluad is manufactured using an egg-based process but contains only trace amounts of egg protein.
Recombinant Vaccine (Flublok Quadrivalent)
Unlike egg-based vaccines, Flublok is made using a recombinant technology that produces the vaccine synthetically, without using influenza viruses or chicken eggs. This makes it a suitable option for individuals with severe egg allergies. The higher concentration of hemagglutinin (HA) in Flublok also helps stimulate a stronger immune response in older adults. Flublok is FDA-approved for individuals aged 9 and older.
Comparison of Preferred Flu Vaccines for Older Adults
| Vaccine Type | Brand Name | Key Feature | Manufacturing Method | Egg-Free? |
|---|---|---|---|---|
| High-Dose | Fluzone High-Dose Quadrivalent | 4x antigen concentration | Egg-based | No |
| Adjuvanted | Fluad Quadrivalent | Contains adjuvant MF59 | Egg-based | No (traces) |
| Recombinant | Flublok Quadrivalent | Recombinant HA | Non-egg-based | Yes |
What if a Preferred Vaccine Isn't Available?
While the CDC preferentially recommends the enhanced options, healthcare experts emphasize that getting any age-appropriate flu vaccine is better than receiving no vaccine at all. If a high-dose, adjuvanted, or recombinant vaccine is not available at your vaccination site, you should get the standard-dose vaccine that is offered. Studies show standard-dose shots still provide valuable protection against severe outcomes in older adults.
What About the Nasal Spray Vaccine?
The live attenuated influenza vaccine (LAIV), or nasal spray vaccine (FluMist), is not recommended for adults aged 50 and older, including seniors. It is only approved for healthy, non-pregnant individuals between the ages of 2 and 49.
Choosing the Right Option for You
Because the CDC does not rank the three preferred vaccines in order of superiority, the choice of which vaccine to receive can depend on individual factors. For most, the most important step is simply getting one of the preferentially recommended options. For those with a severe egg allergy, Flublok is the recommended egg-free choice. Consulting with your healthcare provider is the best way to discuss your personal health history and decide which vaccine is best suited for your needs. The National Council on Aging provides excellent resources on the topic to help with this conversation.
Conclusion
For older adults aged 65 and over, the answer to which is the best flu vaccine for seniors is clear: choose one of the CDC-preferred enhanced options. These include high-dose (Fluzone High-Dose), adjuvanted (Fluad), or recombinant (Flublok) vaccines, all designed to provide superior immune protection for this high-risk group. However, in the event these are not available, opting for a standard-dose vaccine is a wise and recommended choice. Protecting against influenza is vital, and getting an annual flu shot remains the single most effective action an older adult can take to prevent severe illness and its complications. For more information, visit the CDC's Flu & People 65 Years and Older page.
