Updates to the Advisory Committee on Immunization Practices (ACIP) Flu Vaccine Recommendations for the 2023-2024 season

A couple of things are different for the 2023-2024 influenza (flu) season:

• The composition of flu vaccines has been updated. Flu vaccines for the U.S. 2023-2024 season will contain the following:
  Egg-based vaccines
  • an A/Victoria/4897/2022 (H1N1)pdm09-like virus; (Updated)
  • an A/Darwin/9/2021 (H3N2)-like virus;
  • a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
  • a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

• Cell- or recombinant-based vaccines
  • an A/Wisconsin/67/2022 (H1N1)pdm09-like virus; (Updated)
  • an A/Darwin/6/2021 (H3N2)-like virus;
  • a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
  • a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.
  • These recommendations include one update compared to the 2022-2023 U.S. flu vaccine composition. The influenza A(H1N1)pdm09 vaccine virus component was updated for egg-based and cell- or recombinant-based flu vaccines.

• People with egg allergy may get any vaccine (egg-based or non-egg-based) that is otherwise appropriate for their age and health status. Previously, it was recommended that people with severe allergy to egg (those who have had any symptom other than hives with egg exposure) be vaccinated in an inpatient or outpatient medical setting. Beginning with the 2023-2024 season, additional safety measures are no longer recommended for flu vaccination of people with an egg allergy beyond those recommended for receipt of any vaccine, regardless of the severity of previous reaction to egg. All vaccines should be given in settings where allergic reactions can be recognized and treated quickly.

Projected U.S. Flu Vaccine Supply for the 2023-2024 Season

• Vaccine manufacturers have projected that they will supply the United States with as many as 156.2 million to 170 million doses of influenza vaccines for the 2023-2024 season. These projections may change as the season progresses.
  • All flu vaccines for the 2023-2024 season will be quadrivalent (four-component).
  • Most will be thimerosal-free or thimerosal-reduced vaccines (91%), and about 21% of flu vaccines will be egg-free.

To learn more, please visit https://www.cdc.gov/flu/season/faq-flu-season-2023-2024.htm.