Table 1.

Clinical trials, participants, and vaccines.

Trial	Trial group	N	Vaccination schedule	Immune response sampling schedule
Homologous prime-boost studies in adults
Trial 1: A/H1N125	A/H1N1 AS03	29	A/California/07/2009 3.75 µg + AS03A on D0 and D21 Seasonal IIV3 on D42	D0, D21, D42, D182
	A/H1N1 non-adjuvanted	29	A/California/07/2009 15 µg on D0 and D21 Seasonal IIV3 on D42
Trial 2: A/H5N126	A/H5N1 AS03	29	A/Indonesia/5/2005 3.75 µg + AS03A on D0 and D21	D0, D21, D42, D182, D385
	A/H5N1 non-adjuvanted	27	A/Indonesia/5/2005 15 µg on D0 and D21
Trial 3: A/H9N227	A/H9N2 AS03	30	A/chicken/Hong Kong/G9/1997 3.75 µg + AS03A on D0 and D21	D0, D21, D42, D182
	A/H9N2 non-adjuvanted	30	A/chicken/Hong Kong/G9/1997 15 µg on D0 and D21
Seasonal IIV4 study in adults
Trial 4: IIV428	IIV4 non-adjuvanted	30	Seasonal IIV4 15 µg per strain at D0 A/Christchurch/16/2010 (H1N1 pdm09) A/Texas/50/2012 (H3N2) B/Massachusetts/02/2012 (B Yamagata) B/Brisbane/60/2008 (B Victoria)	D0, D21
Heterologous prime-boost studies in adults
Trial 5: A/H5N1 booster29	A/H5N1 AS03 Indonesia > Turkey	26	A/Indonesia/5/05 3.75 µg + AS03A on D0 Placebo on D182 A/turkey/Turkey/1/2005 3.75 µg + AS03A on D549	D0, D42, D182, D224, D549, D591, D729
	A/H5N1 AS03 Turkey > Turkey	29	Placebo on D0 A/turkey/Turkey/1/2005 3.75 µg + AS03A on D182 and D549
Trial 6: A/H5N1 booster30,31	A/H5N1 AS03 Vietnam > Vietnam	53	A/Vietnam/1194/2004 3.75 µg + AS03A on D0 and D365	D0, D21, D182, D365, D385, D549
	A/H5N1 AS03 Vietnam > Indonesia	49	A/Vietnam/1194/2004 + AS03A on D0 A/Indonesia/5/05 3.75 µg + AS03A on D365
Homologous prime-boost study in children
Trial 7: A/H5N132	A/H5N1 AS03	33	A/Indonesia/5/2005 1.90 µg + AS03B at D0 and D21	D0, D21, D42, D385
	Placebo	20	Placebo at D0 and D21

^aTrials 1, 2 and 3: serum samples from participants who received adjuvanted vaccine were randomly selected, and samples matched by age and study center were then selected from the non-adjuvanted group

^bTrial 4: serum samples from participants 18−39 years of age were randomly selected

^cTrials 5 and 6: all evaluable samples from eligible participants were used (i.e. no random selection)

^dTrial 7: only samples from children (6−35 months) who were seronegative for A/H1N1pdm09 (A/California/07/2009-like) antibodies were selected to ensure that the children had not been primed through prior exposure to A/H1N1 virus. Not all study groups in the original trials were included; only the vaccines that were administered to participants whose samples were used in the present study are shown. IIV3: trivalent inactivated influenza vaccine; IIV4: quadrivalent inactivated influenza vaccine