Skip to main content

Table 2 Summary of immunogenicity for the per-protocol cohort

From: Immunogenicity and safety of quadrivalent versus trivalent inactivated influenza vaccine: a randomized, controlled trial in adults

Treatment groupa
Vaccine Strain   QIV LD QIV-AS LD TIV-AS TIV
Nb   104 104 104 105
A/Solomon Islands      
 GMT (95% CI) Pre 21.4 (16.1–28.4) 22.2 (16.6–29.5) 23.3 (17.5–31.0) 18.4 (14.3–23.7)
  Post 130.0 (106.1–159.4) 150.6 (118.4–191.5) 160.4 (129.1–199.3) 133.8 (105.6–169.7)
 SCR %(95% CI) Post 56.7 (46.7–66.4)*$ 57.7 (47.6–67.3)* $ 54.8 (44.7–64.6)* $ 60.0 (50.0–69.4)* $
 SPR %(95% CI) Pre 37.5 (28.2–47.5) 42.3 (32.7–52.4) 40.4 (30.9–50.5) 35.2 (26.2–45.2)
  Post 92.3 (85.4–96.6)* $ 88.5 (80.7–93.9)* $ 93.3 (86.6–97.3)* $ 90.5 (83.2–95.3)* $
 SCF (95% CI) Post 6.1 (4.6–8.0)* 6.8 (5.0–9.2)* 6.9 (5.0–9.4)* 7.3 (5.3–9.9)*
A/Wisconsin      
 GMT (95% CI) Pre 29.3 (23.0–37.3) 25.7 (19.8–33.3) 30.7 (23.7–39.8) 29.0 (22.5–37.4)
  Post 162.1 (138.0–190.4) 189.5 (158.9–226.0) 197.9 (169.1–231.7) 156.3 (127.5–191.6)
 SCR %(95% CI) Post 60.6 (50.5–70.0)* $ 66.3 (56.4–75.3)* $ 64.4 (54.4–73.6)* $ 59.0 (49.0–68.5)* $
 SPR %(95% CI) Pre 51.0 (41.0–60.9) 46.2 (36.3–56.2) 53.8 (43.8–63.7) 55.2 (45.2–65.0)
  Post 97.1 (91.8–99.4)* $ 98.1 (93.2–99.8)* $ 100 (96.5–100)* $ 96.2 (90.5–99.0)* $
 SCF (95% CI) Post 5.5 (4.4–6.9)* 7.4 (5.8–9.4)* 6.4 (5.0–8.3)* 5.4 (4.1–7.0)*
B/Malaysia      
 GMT (95% CI) Pre 32.2 (24.8–41.8) 26.6 (20.2–35.0) 23.2 (17.7–30.4) 27.2 (20.6–35.8)
  Post 192.8 (159.6–232.9) 213.0 (174.0–260.9) 187.0 (151.9–230.3) 188.5 (150.0–237.0)
 SCR %(95% CI) Post 57.7 (47.6–67.3)* $ 65.4 (55.4–74.4)* $ 56.7 (46.7–66.4)* $ 59.0 (49.0–68.5)* $
 SPR %(95% CI) Pre 51.0 (41.0–60.9) 47.1 (37.2–57.2) 42.3 (32.7–52.4) 44.8 (35.0–54.8)
  Post 97.1 (91.8–99.4)* $ 97.1 (91.8–99.4)* $ 96.2 (90.4–98.9)* $ 93.3 (86.7–97.3)* $
 SCF (95% CI) Post 6.0 (4.7–7.7)* 8.0 (6.1–10.5)* 8.1 (5.9–11.0)* 6.9 (5.2–9.3)*
B/Jiangsu      
 GMT (95% CI) Pre 19.6 (15.6–24.8) 19.5 (15.4–24.5) 23.4 (18.3–29.7) 19.2 (15.2–24.3)
  Post 179.1 (151.4–211.9) 158.3 (130.7–191.9) 59.2 (47.3–74.0) 43.4 (34.5–54.6)
 SCR %(95% CI) Post 76.0 (66.6–83.8)* $ 78.8 (69.7–86.2)* $ 26.9 (18.7–36.5) 19.0 (12.0–27.9)
 SPR %(95% CI) Pre 31.7 (22.9–41.6) 38.5 (29.1–48.5) 43.3 (33.6–53.3) 39.0 (29.7–49.1)
  Post 98.1 (93.2–99.8)* $ 95.2 (89.1–98.4)* $ 75.0 (65.6–83.0)* 63.8 (53.9–73.0)
 SCF (95% CI) Post 9.1 (7.2–11.5)* 8.1 (6.6–10.0)* 2.5 (2.1–3.0)* 2.3 (1.9–2.6)
  1. a Groups were administered the quadrivalent influenza vaccine (QIV), the low-dose adjuvanted quadrivalent influenza vaccine (LD QIV-AS), the low-dose adjuvanted trivalent influenza vaccine (LD TIV-AS) or the trivalent influenza vaccine (TIV).
  2. b Abbreviations: 95% CI = 95% confidence interval (lower limit–upper limit); GMT = geometric mean titer; N = total number of participants; Pre = Pre-vaccination (Day 0); Post = Post-vaccination (Day 21); SCR = Seroconversion ratio defined as percentage of participants with antibody titer ≥1:40 1/DIL post-vaccination for initially seronegative participants, or ≥4 fold the pre-vaccination antibody titer for initially seropositive participants; SPR = Seroprotection rate defined as percentage of participants with antibody titer ≥1:40; SCF = Seroconversion factor defined as the fold increase in GMTs post-vaccination compared with pre-vaccination.
  3. * CHMP criteria were met or exceeded (SCR > 40%, SPR > 70%, SCF > 2.5).
  4. $ CBER criteria were met or exceeded (95% CI lower limit for SCR ≥ 40%, SPR ≥ 70%).