Efficacy and safety of a booster dose of the meningococcal A, C, W, Y-tetanus toxoid conjugate vaccine administered 10 years after primary vaccination and long-term persistence of tetanus toxoid conjugate or polysaccharide vaccine

Figures & data

Table 1. Subject demographics in the MenACWY-TT booster phase (booster total vaccinated cohort).

Demographic	Primary MenACWY-TT	Primary MenACWY-PS
Total enrolled, n	170	59
Total completed visits, n	169	58
Sex, n (%)
Male	90 (52.9)	36 (61.0)
Female	80 (47.1)	23 (39.0)
Age at enrollment, y
Mean (SD)	24.2 (1.9)	24.0 (2.0)
Median (range)	24.0 (21–27)	24.0 (21–28)
Race, n (%)
Asian/Southeast Asian	170 (100)	59 (100)
Time since last vaccination at each visit
Primary (Visit 1), weeks, mean (SD)	530.2 (8.3)	531.5 (9.2)
Booster (Visit 2), weeks, mean (SD)	4.8 (0.6)	4.7 (0.4)

MenACWY-PS = quadrivalent meningococcal polysaccharide vaccine; MenACWY-TT = quadrivalent meningococcal tetanus toxoid conjugate vaccine; SD = standard deviation.

Figure 1. Percentages of subjects with booster responses for serogroups A, C, W, and Y at 1 month after booster dose of MenACWY-TT (booster ATP cohort). ATP = according-to-protocol; MenACWY-PS = quadrivalent meningococcal polysaccharide vaccine; MenACWY-TT = quadrivalent meningococcal tetanus toxoid conjugate vaccine.

Table 2. GMTs for serogroups A, C, W, and Y before and 1 month after a booster dose of MenACWY-TT (booster ATP cohort).

	N	Prebooster GMT (95% CI)	1 Month Postbooster GMT (95% CI)
Serogroup A
MenACWY-TT	162	248.4 (181.4–340.2)	3760.1 (3268.3–4325.9)
MenACWY-PS	51	142.7 (80.5–252.9)	2956.0 (2040.5–4282.1)
Serogroup C
MenACWY-TT	162	244.2 (181.6–328.5)	8697.7 (7391.2–10,235.1)
MenACWY-PS	51	177.4 (86.1–365.3)	3879.3 (2714.6–5543.7)
Serogroup W
MenACWY-TT	162	145.5 (97.6–217.1)	11,243.4 (9366.8–13,496.0)
MenACWY-PS	51	16.4 (9.2–29.4)	3674.0 (2353.9–5734.4)
Serogroup Y
MenACWY-TT	162	446.5 (332.7–599.1)	7584.8 (6748.4–8524.7)
MenACWY-PS	51	32.9 (17.1–63.3)	3295.5 (1998.7–5433.7)

ATP = according to protocol; GMT = geometric mean titer; MenACWY-PS = quadrivalent meningococcal polysaccharide vaccine; MenACWY-TT = quadrivalent meningococcal tetanus toxoid conjugate vaccine.

Table 3. Percentage of subjects with anti-tetanus toxoid concentrations ≥0.1 IU/mL and ≥1.0 IU/mL and GMCs before and 1 month after booster dose of MenACWY-TT (booster ATP cohort).

	Prebooster	1 Month Postbooster
MenACWY-TT
≥0.1 IU/mL, n/N (%; 95% CI)	140/162 (86.4; 80.2–91.3)	160/162 (98.8; 95.6–99.9)
≥1.0 IU/mL, n/N (%; 95% CI)	62/162 (38.3; 30.8–46.2)	149/162 (92.0; 86.7–95.7)
GMC (95% CI)	0.608 (0.476–0.775)	5.057 (4.274–5.984)
MenACWY-PS
≥0.1 IU/mL, n/N (%; 95% CI)	28/51 (54.9; 40.3–68.9)	49/51 (96.1; 86.5–99.5)
≥1.0 IU/mL, n/N (%; 95% CI)	14/51 (27.5; 15.9–41.7)	42/51 (82.4; 69.1–91.6)
GMC (95% CI)	0.252 (0.154–0.411)	5.115 (3.073–8.514)

ATP = according to protocol; GMC = geometric mean concentration; MenACWY-PS = quadrivalent meningococcal polysaccharide vaccine; MenACWY-TT = quadrivalent meningococcal tetanus toxoid conjugate vaccine; N = number of subjects; n = number of subjects in a given category.

Figure 2. Percentages of subjects with rSBA titers (A) ≥1:8 and (B) ≥1:128 at Year 10 (before booster) and at 1 month after a booster dose of MenACWY-TT (booster ATP cohort). ATP = according-to-protocol; MenACWY-PS = quadrivalent meningococcal polysaccharide vaccine; MenACWY-TT = quadrivalent meningococcal tetanus toxoid conjugate vaccine; rSBA = serum bactericidal antibody assay using baby rabbit complement.

Figure 3. Percentages of subjects reporting solicited local and general events during 4-day follow-up to booster vaccination (booster total vaccinated cohort). Intensity scale (mild, moderate, or severe) was classified by grade 1, 2, or 3, respectively, for pain, fatigue, GI event, and headache; and 0–≤20 mm, >20–≤50 mm, or >50 mm for redness and swelling. GI = gastrointestinal; MenACWY-PS = quadrivalent meningococcal polysaccharide vaccine; MenACWY-TT = quadrivalent meningococcal tetanus toxoid conjugate vaccine.