No, Quadrivalent Influenza Vaccines Are NOT Available in 2026
For the 2025-26 influenza season, only trivalent (3-strain) influenza vaccines are available—quadrivalent (4-strain) vaccines have been discontinued following WHO guidance to remove the B/Yamagata component. 1
The Transition from Quadrivalent to Trivalent
The shift away from quadrivalent vaccines occurred because the influenza B/Yamagata lineage has been eliminated from global circulation, making the fourth vaccine component unnecessary. 2 The WHO subsequently recommended removing the B/Yamagata antigen from all influenza vaccines, resulting in the universal transition to trivalent formulations for the 2025-26 season.
What's Available for 2025-26
According to the most recent ACIP guidelines, the following trivalent formulations are expected to be available 1:
- Trivalent inactivated influenza vaccines (IIV3s) - multiple formulations
- Trivalent recombinant influenza vaccine (RIV3) - now approved for ages ≥9 years (previously ≥18 years) 1
- Trivalent live attenuated influenza vaccine (LAIV3) - now approved for self-administration (ages 18-49) or caregiver administration (ages 2-17) 1
Key Vaccination Recommendations for 2025-26
All persons aged ≥6 months should receive routine annual influenza vaccination unless contraindicated. 1
Age-Specific Guidance:
- Adults 18-64 years (not pregnant/immunocompromised): Standard-dose trivalent vaccine 3
- Adults ≥65 years: High-dose trivalent vaccine preferred 3
- Children ≤18 years, pregnant women, and all adults: Should receive only single-dose formulations free of thimerosal preservative 1
Timing Considerations:
- Optimal timing: September or October for most individuals 1
- Avoid July-August vaccination in adults ≥65 years and pregnant women in first/second trimester due to immunity waning concerns 1
- Exception for children needing 2 doses: Start as early as possible (including July-August) to complete the 2-dose series by end of October 1
Clinical Implications
The transition to trivalent vaccines does not diminish vaccine value or effectiveness—it reflects successful disease surveillance and elimination of a circulating strain. 2 The remaining three strains (including one B/Victoria lineage) continue to provide comprehensive protection against currently circulating influenza viruses.
Common pitfall to avoid: Do not delay vaccination waiting for quadrivalent formulations—they are no longer manufactured or necessary for the 2025-26 season.