Figure 1

Participant flow. Footnote: TVC, total vaccinated cohort; all participants received inactivated trivalent influenza vaccine; control ≥65 years and control 18–40 years received non-adjuvanted vaccine; eight groups aged ≥65 years received vaccine formulated with an adjuvant. AS03 is a squalene and α-tocopherol oil-in-water emulsion-based Adjuvant System (tocopherol content: A, 11.86 mg; B, 5.93 mg; C, 2.97 mg); MPL is 3-O-desacyl-4’- monophosphoryl lipid A (MPL content: 25, 25 μg; 50, 50 μg).