Head-to-head comparison of an intradermal and a virosome influenza vaccine in patients over the age of 60

Figures & data

Table 1. Safety and tolerability assessment after vaccination with intradermal and virosomal-intramuscular vaccine

	Vaccine route of administration and adjuvant		p-value
	Intradermal	Virosomal Intramuscular
Solicited injection site reactions, days 0–7 (%, 95% C.I)
At least one	43 (36–49)	20 (15–26)	< 0.01
Pain	13 (9–18)	12 (8–17)	NS
Pruritus	20 (16–26)	5 (3–9)	< 0.01
Erythema	33 (27–39)	7 (4–11)	< 0.01
Swelling	19 (14–24)	5 (2–8)	< 0.01
Induration	25 (20–31)	7 (4–11)	< 0.01
Ecchymosis	6 (4–10)	5 (2–8)	NS
Solicited systemic reactions, days 0–7 (%, 95% C.I)
At least one	11 (7–15)	10 (7–15)	NS
Fever	2 (1–4)	2 (1–4)	NS
Headache	4 (2–8)	6 (3–10)	NS
Malaise	5 (3–9)	6 (3–10)	NS
Myalgia	6 (4–10)	7 (4–11)	NS
Shivering	3 (2–6)	5 (3–9)	NS
Unsolicited events, days 0–21 (%, 95% C.I)	2 (0,88; 0,24–3,15)	4 (2,00; 0,78–5,03)	NS
SAEs, days 0–180 (%, 95% C.I)	0	0	NS

Table 2. Antibody response determined by using HI assays after vaccination with intradermal and virosomal-intramuscular vaccine

	Vaccine route of administration and adjuvant		p-value
	Intradermal	Virosomal Intramuscular
Geometric Mean Titer 1 mo post-vaccination
A(H1N1) vaccine strain	48 (29–77)	32 (21–50)	NS
A(H3N2) vaccine strain	41 (28–60)	26 (18–35)	NS
B vaccine strain	131 (90–191)	93 (69–125)	NS
A/Genoa/1/11(H1N1)	69 (42–115)	47 (25–87)	NS
A/Genoa/6/11(H1N1)	71.3 (40–126)	31 (19–53)	< 0.05
A/Genoa/24/11(H1N1)	42 (25–72)	31 (15–65)	NS
Mean Fold Increase 1 mo post-vaccination
A(H1N1) vaccine strain	3.4 (1.9–5.9)	2.3 (1.3–3.8)
A(H3N2) vaccine strain	2.9 (1.8–4.8)	2.1 (1.4–3.1)
B vaccine strain	2.7 (1.5–4.9)	1.5 (1–2.3)
A/Genoa/1/11(H1N1)	4.1 (2.2–7.6)	3.7 (1.8–7.6)
A/Genoa/6/11(H1N1)	4.8 (2.3–9.7)	3.3 (1.7–6.5)
A/Genoa/24/11(H1N1)	2.8 (1.5–5.5)	2.6 (1.1–6.1)
Seroconversion rate 1 mo post-vaccination (%, 95% C.I.)
A(H1N1) vaccine strain	50 (31–69)	43 (26–43)	NS
A(H3N2) vaccine strain	50 (31–69)	35 (19–55)	NS
B vaccine strain	46 (28–65)	0 (0–14)	< 0.05
A/Genoa/1/11(H1N1)	63 (43–79)	43 (26–63)	NS
A/Genoa/6/11(H1N1)	67 (47–82)	48 (29–67)	NS
A/Genoa/24/11(H1N1)	42 (25–61)	35 (19–55)	NS
Seroprotection rate 1 mo post-vaccination (%, 95% C.I.)
A(H1N1) vaccine strain	63 (43–79)	57 (37–74)	NS
A(H3N2) vaccine strain	71 (51–85)	48 (29–67)	NS
B vaccine strain	100 (86–100)	100 (86–100)	NS
A/Genoa/1/11(H1N1)	79 (60–91)	70 (49–84)	NS
A/Genoa/6/11(H1N1)	79 (60–91)	52 (33–71)	NS
A/Genoa/24/11(H1N1)	75 (55–88)	52 (33–71)	NS
Geometric Mean Titer 3 mo post-vaccination
A(H1N1) vaccine strain	39 (22–67)	26 (17–40)	NS
A(H3N2) vaccine strain	36 (24–55)	19 (14–27)	< 0.05
B vaccine strain	130 (81–209)	93 (65–132)	NS
A/Genoa/1/11(H1N1)	59 (30–115)	30 (16–56)	NS
A/Genoa/6/11(H1N1)	72 (34–152)	23 (14–38)	< 0.05
A/Genoa/24/11(H1N1)	41 (23–76)	31 (14–67)	NS
Seroprotection rate 3 mo post-vaccination (%, 95% C.I.)
A(H1N1) vaccine strain	45 (26–66)	47 (27–68)	NS
A(H3N2) vaccine strain	60 (39–78)	32 (15–54)	NS
B vaccine strain	95 (76–99)	100 (83–100)	NS
A/Genoa/1/11(H1N1)	70 (48–86)	53 (32–73)	NS
A/Genoa/6/11(H1N1)	70 (48–86)	47 (27–68)	NS
A/Genoa/24/11(H1N1)	75 (53–89)	58 (36–77)	NS

Table 3. Antibody response determined by using NT assays after vaccination with intradermal and virosomal/intramuscular vaccine

	Vaccine route of administration and adjuvant		p-value
	Intradermal	Virosomal Intramuscular
Geometric Mean Titer 1 mo post-vaccination
A(H1N1) vaccine strain	28 (17–44)	19 (12–31)	NS
A/Genoa/1/11(H1N1)	80 (44–147)	44 (23–84)	NS
A/Genoa/6/11(H1N1)	90 (48–169)	37 (19–69)	< 0.05
A/Genoa/24/11(H1N1)	49 (28–86)	20 (11–37)	< 0.05
A/Genoa/89/11(H1N1)	35 (20–61)	20 (10–38)	NS
Mean Fold Increase 1 mo post-vaccination
A(H1N1) vaccine strain	3.5 (2–6)	2.4 (1.3–4.3)
A/Genoa/1/11(H1N1)	4.9 (2.3–10.5)	4 (1.9–8.9)
A/Genoa/6/11(H1N1)	5.8 (2.8–12)	3.9 (1.8–8.1)
A/Genoa/24/11(H1N1)	3.7 (1.9–7.1)	2.5 (1.2–5)
A/Genoa/89/11(H1N1)	4.2 (2.3–7.9)	2.5 (1.3–5.2)
Seroconversion rate 1 mo post-vaccination (%, 95% C.I.)
A(H1N1) vaccine strain	54 (35–72)	44 (26–63)	NS
A/Genoa/1/11(H1N1)	54 (35–72)	48 (30–67)	NS
A/Genoa/6/11(H1N1)	58 (39–76)	30 (16–51)	NS
A/Genoa/24/11(H1N1)	58 (39–76)	39 (22–59)	NS
A/Genoa/89/11(H1N1)	50 (31–69)	26 (13–47)	NS
Titer ≥ 40 rate 1 mo post-vaccination (%, 95% C.I.)
A(H1N1) vaccine strain	58 (39–76)	48 (29–67)	NS
A/Genoa/1/11(H1N1)	75 (55–88)	65 (45–81)	NS
A/Genoa/6/11(H1N1)	75 (55–88)	44 (26–63)	< 0.05
A/Genoa/24/11(H1N1)	79 (60–91)	39 (22–59)	< 0.05
A/Genoa/89/11(H1N1)	54 (35–72)	30 (16–51)	NS
Geometric Mean Titer 3 mo post-vaccination
A(H1N1) vaccine strain	22 (13–37)	13 (8–20)	NS
A/Genoa/1/11(H1N1)	46 (25–85)	27 (15–48)	NS
A/Genoa/6/11(H1N1)	57 (30–105)	22 (12–37)	< 0.05
A/Genoa/24/11(H1N1)	51 (27–95)	14 (10–27)	< 0.05
A/Genoa/89/11(H1N1)	25 (14–43)	11 (7–19)	< 0.05
Titer ≥ 40 rate 3 mo post-vaccination (%, 95% C.I.)
A(H1N1) vaccine strain	55 (34–74)	32 (15–54)	NS
A/Genoa/1/11(H1N1)	60 (39–78)	42 (23–64)	NS
A/Genoa/6/11(H1N1)	65 (43–82)	37 (19–59)	NS
A/Genoa/24/11(H1N1)	75 (53–89)	21 (9–43)	< 0.05
A/Genoa/89/11(H1N1)	45 (26–66)	21 (9–43)	NS

Figure 1. Molecular and serological characterization of influenza strains used in the study. Phylogenetic tree based on sequence analysis of the region codifying for the globular head region of haemagglutinin of strains used in the study, amino acid mutations onto-antigenic sites with respect to vaccine A/California/04/09(H1N1)pdm09 strain and serological characterization of isolated and reference viruses, performed with the HI test using whole viruses and post-infection ferret sera.