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Table 2 Haemagglutination inhibition (HI) antibody immune responses to homologous and heterologous H5N1 influenza strains following one or two doses of the AS03A-adjuvanted A/Indonesia/5/2005 (H5N1) influenza vaccine were assessed in terms of seropositivity rates, GMTs, SCRs, SCFs and SPRs.

From: A phase II, open-label, multicentre study to evaluate the immunogenicity and safety of an adjuvanted prepandemic (H5N1) influenza vaccine in healthy Japanese adults

    Seropositivity rates GMT SCR
(Negative pre-vaccination HI titre and P/V HI titre ≥1:40, or proportion with ≥4-fold increase from pre- to post vaccination)
SCF
(Mean GMT increase in titre >2.5 [adults]; >2.0 [aged over 60 y])
SPR
(% subjects with P/V HI titre ≥1:40)
Antibody Group D N n % (95% CI) Value (95% CI) N n % (95% CI) N Value (95% CI) N n % (95% CI)
A/Indonesia 20-40 Y 0 50 0 0.0 (0.0-7.1) 5.0 (5.0-5.0) - - - - - 50 0 0.0 (0.0-7.1)
   21 50 24 48.0 (33.7-62.6) 15.8 (11.0-22.8) 50 19 38.0 (24.7-52.8) 50 3.2 (2.2-4.6) 50 19 38.0 (24.7-52.8)
   42 50 45 90.0 (78.2-96.7) 156.8 (105.8-232.3) 50 45 90.0 (78.2-96.7) 50 31.4 (21.2-46.5) 50 45 90.0 (78.2-96.7)
   182 49 30 61.2 (46.2-74.8) 25.6 (17.3-38.1) 49 29 59.2 (44.2-73.0) 49 5.1 (3.5-7.6) 49 29 59.2 (44.2-73.0)
  41-64 Y 0 50 5 10.0 (3.3-21.8) 5.4 (5.0-5.8) - - - - - 50 0 0.0 (0.0-7.1)
   21 50 27 54.0 (39.3-68.2) 15.4 (10.7-22.0) 50 16 32.0 (19.5-46.7) 50 2.8 (2.0-4.0) 50 16 32.0 (19.5-46.7)
   42 50 48 96.0 (86.3-99.5) 142.1 (104.0-194.3) 50 46 92.0 (80.8-97.8) 50 26.2 (19.2-35.8) 50 46 92.0 (80.8-97.8)
   182 50 40 80.0 (66.3-90.0) 37.4 (27.5-50.8) 50 38 76.0 (61.8-86.9) 50 6.9 (5.1-9.2) 50 38 76.0 (61.8-86.9)
A/turkey/Turkey 20-40 Y 0 50 2 4.0 (0.5-13.7) 5.7 (4.8-6.8) - - - - - 50 2 4.0 (0.5-13.7)
   21 50 13 26.0 (14.6-40.3) 8.0 (6.1-10.4) 50 3 6.0 (1.3-16.5) 50 1.4 (1.1-1.8) 50 5 10.0 (3.3-21.8)
   42 50 30 60.0 (45.2-73.6) 24.8 (16.6-37.1) 50 27 54.0 (39.3-68.2) 50 4.4 (3.0-6.5) 50 29 58.0 (43.2-71.8)
   182 49 30 61.2 (46.2-74.8) 19.2 (13.4-27.3) 49 18 36.7 (23.4-51.7) 49 3.4 (2.4-4.7) 49 20 40.8 (27.0-55.8)
  41-64 Y 0 50 2 4.0 (0.5-13.7) 5.2 (4.9-5.5) - - - - - 50 0 0.0 (0.0-7.1)
   21 50 18 36.0 (22.9-50.8) 9.6 (7.3-12.5) 50 7 14.0 (5.8-26.7) 50 1.8 (1.4-2.4) 50 8 16.0 (7.2-29.1)
   42 50 31 62.0 (47.2-75.3) 24.0 (16.1-35.6) 50 27 54.0 (39.3-68.2) 50 4.6 (3.1-6.8) 50 27 54.0 (39.3-68.2)
   182 50 38 76.0 (61.8-86.9) 30.7 (22.2-42.5) 50 30 60.0 (45.2-73.6) 50 5.9 (4.2-8.2) 50 30 60.0 (45.2-73.6)
A/Vietnam 20-40 Y 0 50 1 2.0 (0.1-10.6) 5.2 (4.8-5.7) - - - - - 50 1 2.0 (0.1-10.6)
   21 50 5 10.0 (3.3-21.8) 5.7 (5.0-6.5) 50 0 0 (0-7.1) 50 1.1 (1.0-1.2) 50 1 2.0 (0.1-10.6)
   42 50 26 52.0 (37.4-66.3) 12.7 (9.5-17.1) 50 14 28.0 (16.2-42.5) 50 2.4 (1.8-3.2) 50 15 30.0 (17.9-44.6)
   182 49 17 34.7 (21.7-49.6) 8.6 (6.8-10.8) 49 2 4.1 (0.5-14.0) 49 1.6 (1.3-2.1) 49 3 6.1 (1.3-16.9)
  41-64 Y 0 50 5 10.0 (3.3-21.8) 5.9 (5.0-6.8) - - - - - 50 2 4.0 (0.5-13.7)
   21 50 13 26.0 (14.6-40.3) 7.0 (5.8-8.5) 50 1 2.0 (0.1-10.6) 50 1.2 (1.1-1.4) 50 4 8.0 (2.2-19.2)
   42 50 24 48.0 (33.7-62.6) 13.3 (9.7-18.2) 50 12 24.0 (13.1-38.2) 50 2.3 (1.7-3.0) 50 15 30.0 (17.9-44.6)
   182 50 23 46.0 (31.8-60.7) 10.7 (8.2-13.9) 50 10 20.0 (10.0-33.7) 50 1.8 (1.4-2.4) 50 12 24.0 (13.1-38.2)
  1. Subjects received one dose of vaccine on Day 0 and one dose on Day 21 (ATP cohort for immunogenicity and persistence).
  2. 20-40 Y = subjects aged 20-40 years; 41-64 Y = subjects aged 41-64 years; GMT = geometric mean antibody titre; N = number of subjects with available results; n/% = number/percentage of subjects; P/V = post-vaccination; 95% CI = 95% confidence interval; D = Day, 0 = pre-vaccination, 21 = 21 days post vaccination one, 42 = 42 days post vaccination one (i.e. 21 days post vaccination two), 182 = 182 post vaccination one.
  3. Committee for Medicinal Products for Human Use (CHMP) criteria for adults 18-60 years: SCR >40%, SPR >70% and a SCF of >2.5
  4. US Food and Drug Administration (FDA) Center for Biologics Evaluation and Research (CBER) criteria for adults <65 years of age: Lower bound of the two-sided 95% CI for the percentage of subjects achieving seroconversion for HI antibody should meet or exceed 40% and the lower bound of the two-sided 95% CI for the percentage of subjects achieving a seroprotective level of HI antibody titre ≥1:40 should meet or exceed 70%.