Flu Vaccine Effectiveness for Children and Older Adults

What to know

Flu vaccination has been found during most seasons to provide a similar level of protection against flu illness in children to that seen among adults (18-64 years). People 65 years and older are recommended to receive higher dose or adjuvanted flu vaccines because they are more effective for that group.

Close-up of multiple vaccine vials

In Children

Flu vaccination has been found during most seasons to provide a similar level of protection against flu illness in children to that seen among adults 18-64 years. ACIP recommends any licensed, age-appropriate flu vaccine for children without preference for any one flu vaccine over another. In several studies, flu vaccine effectiveness was higher among children who received two doses of flu vaccine the first season that they were vaccinated (as recommended) compared to "partially vaccinated" children who only received a single dose of flu vaccine123.

In addition to preventing illness, flu vaccine can prevent severe, life-threatening complications in children, for example:

  • A 2022 study showed that flu vaccination reduced children's risk of severe life-threatening influenza by 75 percent.
  • A 2020 study found that during the 2018-2019 flu season, flu vaccination reduced flu-related hospitalization by 41 percent and flu-related emergency department visits by half among children (aged 6 months to 17 years old).
  • In 2017, a study in the journal Pediatrics was the first of its kind to show that flu vaccination also significantly reduced a child's risk of dying from flu. The study, which looked at data from four flu seasons between 2010 and 2014, found that flu vaccination reduced the risk of flu-associated death by half (51 percent) among children with underlying, higher risk medical conditions and by nearly two-thirds (65 percent) among healthy children.
  • A 2014 study showed that flu vaccine reduced children's risk of flu-related pediatric intensive care unit (PICU) admission by 74 percent during flu seasons from 2010-2012.

In Older Adults

In numerous studies since 2010, standard dose flu vaccines offered some protection in adults 65 and older against flu illness resulting in a doctor's visit as well as flu-related hospitalization, but protection was inconsistent in this age group during some flu seasons456. As a result, beginning with the 2022-2023 flu season, CDC and the Advisory Committee on Immunization Practices (ACIP) preferentially recommended the use of higher dose and adjuvanted flu vaccines for people 65 years and older. The preference applies to Fluzone High-Dose Trivalent vaccine, Flublok Trivalent recombinant flu vaccine and Fluad Trivalent adjuvanted flu vaccine. This recommendation was based on a review of available studies which suggests that, in this age group, these vaccines are potentially more effective than standard dose unadjuvanted flu vaccines. Because flu viruses and the effectiveness of flu vaccines can vary from one season to another, it is not known whether, in any given flu season, if one of these preferentially recommended flu vaccines will always be more effective in people 65 and older.

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Content Source:
National Center for Immunization and Respiratory Diseases (NCIRD)
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