Evaluation of a new syringe presentation of reduced-antigen content diphtheria, tetanus, and acellular pertussis vaccine in healthy adolescents - A single blind randomized trial

Figures & data

Table 1. Seroprotection/seropositivity rates and GMCs one month after booster vaccination (ATP cohort for immunogenicity)

		dTpa-new				dTpa-previous
Antibody	Timing	N	n	Seroprotection (95% CI)	GMC(95% CI)	N	n	Seroprotection (95% CI)	GMC(95% CI)
anti-diphtheria	Pre	321	284	88.5 (84.5–91.8)	0.472 (0.403–0.553)	319	286	89.7 (85.8–92.8)	0.456 (0.392–0.530)
	Post	321	320	99.7 (98.3–100)	6.784 (6.178–7.450)	319	319	100 (98.9–100)	6.493 (5.915–7.128)
anti-tetanus	Pre	321	311	96.9 (94.3–98.5)	0.956 (0.835–1.095)	319	314	98.4 (96.4–99.5)	0.899 (0.789–1.026)
	Post	321	321	100 (98.9–100)	18.937 (17.313–20.713)	319	319	100 (98.9–100)	18.515 (16.851–20.342)
		dTpa-new				dTpa-previous
Antibody	Timing	N	n	Seropositivity (95% CI)	GMC(95% CI)	N	n	Seropositivity (95% CI)	GMC (95% CI)
anti-PT	Pre	320	175	54.7 (49.1–60.2)	7.5 (6.6–8.7)	319	175	54.9 (49.2–60.4)	7.2 (6.3–8.2)
	Post	318	316	99.4 (97.7–99.9)	140.2 (126.0–156.1)	318	315	99.1 (97.3–99.8)	125.9 (112.7–140.7)
anti-FHA	Pre	316	310	98.1 (95.9–99.3)	48.9 (43.3–55.2)	315	310	98.4 (96.3–99.5)	49.4 (43.6–56.0)
	Post	319	319	100 (98.9–100)	1080.2 (995.2–1172.5)	319	319	100 (98.9–100)	1013.7 (940.0–1093.2)
anti-PRN	Pre	321	269	83.8 (79.3–87.7)	14.0 (12.3–15.9)	319	272	85.3 (80.9–89.0)	13.4 (11.9–15.0)
	Post	321	321	100 (98.9–100)	652.4 (572.1–743.9)	318	318	100 (98.8–100)	619.2 (546.0–702.2)

dTpa-new = Subjects who received Boostrix™ in new syringe presentation; dTpa-previous = Subjects who received Boostrix™ in previous syringe presentation.

N = Number of subjects with both pre- and post-vaccination results available; 95% CI = 95% confidence interval; D, diphtheria; T, tetanus; PT, pertussis toxin; FHA, filamentous hemagglutinin; PRN, pertactin IU, international unit; El.U, ELISA unit; GMC, geometric mean concentration calculated on all subjects.

* Seroprotection=anti-diphtheria and anti-tetanus antibody concentration ≥0.1 IU/mL.

** Seropositive=Anti-PT, Anti-FHA and Anti-PRN antibodies ≥5 EU/mL.

Table 2. Adjusted GMC ratios between groups (dTpa-previous divided by dTpa-new) one month after booster vaccination (ATP cohort for immunogenicity)

	dTpa-previous		dTpa-new		Adjusted GMC ratio (dTpa-pre Group/ dTpa-new Group)
Antibody	N	Adjusted GMC	N	Adjusted GMC	Value (95% CI)
anti-diphtheria	319	6.521	321	6.765	0.96 (0.85–1.09)
anti-tetanus	319	18.672	321	19.171	0.97 (0.86–1.10)
anti-PT	318	128.340	317	138.832	0.92 (0.82–1.04)
anti-FHA	315	1013.167	314	1096.827	0.92 (0.83–1.03)
anti-PRN	318	634.592	321	645.504	0.98 (0.85–1.13)

dTpa-new = Subjects who received Boostrix™ in new syringe presentation; dTpa-previous = Subjects who received Boostrix™ in previous syringe presentation.

N = Number of subjects with both pre- and post-vaccination results available; 95% CI = 95% confidence interval for the adjusted GMC ratio [ANCOVA model: Adjusted for pre-booster concentration and number of previous DT(P)/dT(pa) doses (5 or 6) pooled variance]); LL = lower limit, UL = upper limit.

Adjusted GMC = geometric mean antibody concentration obtained from an ANCOVA model adjusted for pre-booster concentration and number of previous DT(P)/dT(pa) doses (5 or 6).

Figure 1. Incidence of solicited local and general symptoms reported during the 4-day post-vaccination follow-up period (Total Vaccinated Cohort).