Immunogenicity, reactogenicity and safety of an inactivated quadrivalent influenza vaccine candidate versus inactivated trivalent influenza vaccine: a phase III, randomized trial in adults aged ≥18 years

Table 4 Superiority of QIV versus TIVs against alternate lineage B strains according to HI-assay based GMT and SCR at Day 21 in the per-protocol cohort for immunogenicity

Vaccine antigen	TIV-Vic	TIV-Yam	QIV	Superiority analysis
	N = 605	N = 530	N = 1081
	Adjusted GMT			Adjusted GMT ratio (95% CI) ^†
B/Brisbane/3/2007 (Yamagata lineage)	387.7	–	601.2	QIV/TIV-Vic
B/Brisbane/3/2007 (Yamagata lineage)	387.7	–	601.2	1.55 (1.41, 1.70)
B/Brisbane/60/2008 (Victoria lineage)	–	259.4	403.5	QIV/TIV-Yam
B/Brisbane/60/2008 (Victoria lineage)	–	259.4	403.5	1.56 (1.42, 1.70)
	Number seroconverted (SCR)			SCR difference (95% CI) ^‡
B/Brisbane/3/2007 (Yamagata lineage)	276 (45.6%)	–	1112 (61.7%)	QIV minus TIV-Vic
B/Brisbane/3/2007 (Yamagata lineage)	276 (45.6%)	–	1112 (61.7%)	16.12% (11.54, 20.65)
B/Brisbane/60/2008 (Victoria lineage)	–	252 (47.5%)	1046 (58.1%)	QIV minus TIV-Yam
				10.53% (5.70, 15.33)

^†Superiority was demonstrated if the lower limit of the 95% CI was > 1.0; ^‡Superiority was demonstrated if the lower limit of the 95% CI was > 0%.
CI confidence interval, GMT geometric mean titer, HI Hemagglutination inhibition, SCR seroconversion rate (proportion with pre-vaccination titer < 1:10 and a post-vaccination titer ≥ 1:40, or a pre-vaccination titer ≥ 1:10 and at least a four-fold increase in post-vaccination titer), TIV-Vic inactivated trivalent influenza vaccine Victoria lineage B strain, TIV-Yam inactivated trivalent influenza vaccine Yamagata lineage B strain, QIV inactivated quadrivalent influenza vaccine.

ISSN: 1471-2334