Immunogenicity and safety of Intanza^®/IDflu^® intradermal influenza vaccine in South Korean adults: A multicenter, randomized trial

Figures & data

Table 1. Baseline characteristics of study participants

	18−59 y		≥ 60 y
	9 µg ID (n = 60)	15 µg IM (n = 60)	15 µg ID (n = 60)	15 µg IM (n = 60)
Mean age, years ± SD	33.0 ± 9.2	34.5 ± 10.2	64.9 ± 3.6	64.5 ± 3.8
Sex, male (%)	20 (33.3)	18 (30.0)	25 (41.7)	21 (35.0)
Previously vaccinated for seasonal influenza (%)	13 (21.7)	23 (38.3)	27 (45.0)	26 (43.3)
Received 2009/2010 seasonal influenza vaccine (%)	11 (13.3)	21 (35.0)	23 (38.3)	23 (38.3)

Values are numbers of subjects (percent). ID, intradermal vaccine; IM, intramuscular vaccine; SD, standard deviation.

Figure 1. Prevaccination geometric mean titers and seroprotection rates. (A) Geometric mean titers (GMTs) for the 18−59 y age groups at day 0. (B) GMTs for the ≥ 60 y age groups at day 0. (C) Seroprotection rates for the 18−59 y age groups at day 0. (D) Seroprotection rates for the ≥ 60 y age groups at day 0. ID: intradermal vaccine; IM: intramuscular vaccine.

Figure 2. Immunogenicity outcomes after intradermal (ID) or intramuscular (IM) influenza vaccination in the 18−59 y age group. Subjects were vaccinated with 9 μg ID vaccine or with 15 μg IM vaccine, and immunogenicity characteristics were determined 21 d later. (A) Geometric mean titers (GMTs) at day 21. (B) GMT ratios (GMTRs), which were the geometric means of the day 21 hemagglutinin inhibition (HI) titer divided by the pre-vaccination (day 0) HI titer for each subject. (C) Seroprotection rates. Error bars indicate the 95% confidence intervals, and the horizontal bars indicate the Committee for Medicinal Products for Human Use criteria for adults 18–59 y old.

Figure 3. Immunogenicity outcomes after intradermal (ID) or intramuscular (IM) influenza vaccination in the ≥ 60 y age group. Subjects were vaccinated with 15 μg ID vaccine or with 15 μg IM vaccine, and immunogenicity characteristics were determined 21 d later. (A) Geometric mean titers (GMTs) at day 21. (B) GMT ratios (GMTRs), which were the geometric means of the day 21 hemagglutinin inhibition (HI) titer divided by the pre-vaccination (day 0) HI titer for each subject. (C) Seroprotection rates. (D) Seroconversion rates. Error bars indicate the 95% confidence intervals, and the horizontal bars indicate the Committee for Medicinal Products for Human Use criteria for adults ≥ 60 y old.

Figure 4. Solicited injection site and systemic reaction profiles. (A) Solicited injection site reactions. (B) Solicited systemic reactions. Data are the percentages of subjects within each group who experienced a grade 1 or 2 reaction or a grade 3 reaction through post-vaccination day 7. ID: intradermal vaccine; IM: intramuscular vaccine.

Table 2. Unsolicited adverse events

	18−59 y		≥ 60 y
	9 µg ID (n = 60)	15 µg IM (n = 60)	15 µg ID (n = 60)	15 µg IM (n = 60)
All unsolicited AEs (within 21 d)	16 (26.7)	15 (25.0)	14 (23.3)	15 (25.0)
Grade 3	4 (6.7)	2 (3.3)	1 (1.7)	1 (1.7)
Treatment-related	4 (6.7)	2 (3.3)	2 (3.3)	2 (3.3)
Grade 3 treatment-related	0 (0.0)	1 (1.7)	0 (0.0)	0 (0.0)
SAEs	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)

Values are numbers of subjects experiencing at least one reaction, with percent in brackets. AE, adverse event; ID, intradermal vaccine; IM, intramuscular vaccine; SAE, serious adverse event.

Table 3. Committee for Medicinal Products for Human Use-defined solicited reactions

	18–59 y		≥ 60 y
	9 µg ID (n = 60)	15 µg IM (n = 60)	15 µg ID (n = 60)	15 µg IM (n = 60)
Injection site induration ≥ 50 mm for ≥ 3 d	0 (0)	0 (0)	0 (0)	0 (0)
Injection site ecchymosis > 0 mm	2 (3.3)	2 (3.3)	1^a (1.7)	2^a (3.3)
Pyrexia (> 38°C) for ≥ 1 d	0 (0)	0 (0)	0 (0)	0 (0)
Malaise	14 (23.3)	14 (23.3)	12 (20.0)	8 (13.3)
Shivering	11 (18.3)	7 (11.7)	11 (18.3)	8 (13.3)

Except for injection site induration, all were reactions occurring within 3 d of vaccination. Values are numbers of subjects experiencing at least one reaction, with percent in brackets. ID, intradermal vaccine; IM, intramuscular vaccine. ^a One of these subjects reported grade 1 ecchymosis (≥ 2.5 mm).