CDC Revamps Flu Vaccine Recommendation for Older Adults

CDC Medical Officer Lisa Grohskopf, MD, MPH, answers questions about the preferential vaccine recommendations for higher-dose and adjuvanted flu vaccines for adults aged 65 years or older.

For the 2022-2023 flu season, CDC's Advisory Committee on Immunization Practices (ACIP) preferentially recommends the use of specific flu vaccines for adults 65 years or older, including higher-dose and adjuvanted flu vaccines. Before now, there hasn't been a preferential recommendation for a specific vaccine in this population. The preference applies to Fluzone High-Dose Quadrivalent, Flublok Quadrivalent, and Fluad Quadrivalent flu vaccines. There is still no preferential recommendation for people younger than 65. It's recommended that people 65 or older should get one of the three preferentially recommended vaccines; however, if one of these vaccines is not available at the time of administration, people in this age group should get an age-appropriate standard-dose, unadjuvanted flu vaccine instead.

Why were these updates made to flu vaccine recommendations?

While flu seasons vary in severity, during most seasons people 65 years or older bear the greatest burden of severe flu disease, accounting for the majority of flu-related hospitalizations and deaths. In recent years, it's estimated that between 70% and 85% of seasonal flu-related deaths have occurred in people 65 years or older, and between 50% and 70% of seasonal flu-related hospitalizations have occurred among people in this age group. Additionally, changes in the immune system with age mean that older adults often do not have as strong an immune response to vaccination as younger, healthy people. Given the higher risk for severe flu illness and lower protective immune response after vaccination among older adults, substantial research and development have led to the production of flu vaccines intended to provide better immunity for people in this age group. Evidence suggests that these higher-dose and adjuvanted flu vaccines might be more effective in older adults whose immune systems are not as strong as those in younger, healthy people. Given their increased risk for flu-associated severe illness, hospitalization, and death, it's recommended to use these vaccines for people 65 years or older when available.

What evidence is there to back up this preferential recommendation?

CDC's preferential recommendation is based on a review of available studies which suggests that, for this age group, higher-dose and adjuvanted flu vaccines are potentially more effective than standard-dose, unadjuvanted flu vaccines.

What are higher-dose flu vaccines?

Higher-dose flu vaccines include both Fluzone High-Dose Quadrivalent and Flublok Quadrivalent.

Fluzone High-Dose Quadrivalent is approved for people ages 65 years or older. It contains four times the antigen, the part of the vaccine that helps your body build up protection against flu viruses, compared with standard-dose, inactivated flu vaccines. The higher dose of antigen in the vaccine is intended to give people 65 years or older a better immune response to vaccination, and therefore better protection against flu.

Flublok Quadrivalent is a recombinant flu vaccine that is approved for adults ages 18 years or older. It contains three times the antigen, the part of the vaccine that helps your body build up protection against flu viruses, compared with standard-dose, inactivated flu vaccines.

What is an adjuvanted flu vaccine?

Fluad Quadrivalent is a standard-dose, quadrivalent, inactivated flu vaccine approved for people 65 years or older. This vaccine contains an adjuvant called MF59. An adjuvant is an ingredient added to a vaccine that is intended to help create a stronger immune response to vaccination.

What does this change mean for healthcare and vaccine providers?

Healthcare and vaccine providers should continue to make strong flu vaccine recommendations for their patients and recommend higher-dose or adjuvanted flu vaccines over standard-dose, unadjuvanted flu vaccine for their patients aged 65 years or older.

How do the side effects from higher-dose and adjuvanted flu vaccines compare with those of standard-dose flu vaccines?

The common types of side effects from higher-dose or adjuvanted flu vaccines are similar to those from other flu vaccines. Common side effects from flu shots include things such as soreness, redness, and swelling where the shot was given; fever; muscle aches; and nausea. Some of these kinds of side effects might be more common with high-dose and adjuvanted vaccines than with standard-dose vaccines that don't have adjuvant. But in studies of these vaccines, when these side effects occurred, they were usually mild. For the recombinant influenza vaccine, side effects were similar to those from other injectable flu vaccines.

Why is a preferential recommendation for these vaccines necessary?

Given older adults' increased risk for flu-associated severe illness, hospitalization, and death compared with younger populations, it is recommended to use potentially more effective vaccines when possible. A preferential recommendation for the use of higher-dose or adjuvanted vaccines over other age-appropriate vaccines for this population might increase the likelihood that these vaccines will be used, and potentially better protect older adults from the more severe consequences of flu.

Will there be an adequate supply of higher-dose and adjuvanted flu vaccines available for people aged 65 or older this season to meet any increase in demand created by this preferential recommendation?

We are not aware of any supply problems with these higher-dose or adjuvanted flu vaccines as a group.

Are there any other flu vaccine updates for the 2022-2023 flu season?

There are a few other updates since the last season's recommendations were published in August 2021. For the 2022-2023 flu season, the influenza A(H3N2) and influenza B/Victoria components have been updated compared with the 2021-2022 season.

In addition, the age indication for Flucelvax Quadrivalent has been changed to ages 6 months or older. It was previously approved for people 2 years or older.

Like last season, all flu vaccines available in the United States for the 2022-2023 flu season will be quadrivalent.

Can higher-dose and adjuvanted flu vaccines be administered at the same time as COVID-19 vaccines?

During the 2022-2023 influenza season, SARS-CoV-2 is expected to continue to circulate in the United States, and COVID-19 vaccinations are expected to continue. Current guidance for the administration of COVID-19 vaccines indicates that these vaccines can be administered with influenza vaccines; providers should consult this page for updated information.

Do we know how severe the 2022-2023 flu season will be?

Flu activity can be difficult to predict. The most recent season (2021-2022) was mild, but flu viruses circulated at higher levels than during the 2020-2021 season and hospitalization rates surpassed those reported during the 2011-2012 flu season, which was the least severe season in the decade prior to the COVID-19 pandemic. The best way to be protected from a potentially severe 2022-2023 flu season is with a flu vaccine.