The Flu Vaccine Face-Off Ends in a Draw
Pragmatic cluster randomized crossover study found no statistically significant difference in laboratory-confirmed influenza during the 2023-2024 season
By
Kerri Miller
May 8, 2026
Clinical Scorecard: The Flu Vaccine Face-Off Ends in a Draw
At a Glance
Category Detail
Condition Influenza in adults aged 65 years or older
Key Mechanisms Comparison of adjuvanted vs high-dose influenza vaccines
Target Population Adults aged 65 years or older
Care Setting Routine clinical care
Key Highlights
Adjuvanted and high-dose vaccines showed similar effectiveness against laboratory-confirmed influenza. Study involved 429,595 patients from Kaiser Permanente Northern California. No statistically significant difference in effectiveness between vaccine formulations. Influenza A accounted for the majority of cases in both groups. Findings support continued use of either vaccine formulation for older adults.
Guideline-Based Recommendations
Diagnosis
Polymerase chain reaction testing for confirmed influenza.
Management
Both adjuvanted and high-dose vaccines are recommended for adults aged 65 years or older.
Monitoring & Follow-up
Monitor for polymerase chain reaction-confirmed influenza and associated hospitalizations.
Risks
Potential underrepresentation of milder influenza cases due to testing propensity.
Patient & Prescribing Data
Adults aged 65 years or older
Both vaccine formulations are effective; choice may depend on patient preference.
Clinical Best Practices
Continue to offer both adjuvanted and high-dose vaccines to older adults. Consider local influenza circulation and geographic variation when administering vaccines.
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