Table 2.

Solicited injection site and systemic adverse reactions occurring within 7 days and unsolicited adverse events (by system organ class) occurring within 30 days after any dose of vaccine or placebo (safety analysis set).

	C. difficile toxoid vaccine		Placebo
	(N = 68)		(N = 34)
Adverse event	n (%)	95% CI	n (%)	95% CI
Solicited adverse reactions
Any solicited reaction	46 (67.6%)	55.2;78.5	7 (20.6%)	8.7;37.9
Injection site reactions	46 (67.6%)	55.2;78.5	5 (14.7%)	5.0;31.1
Pain	46 (67.6%)	55.2;78.5	5 (14.7%)	5.0;31.1
Erythema	11 (16.2%)	8.4;27.1	0	0.0;10.3
Swelling	8 (11.8%)	5.2;21.9	0	0.0;10.3
Systemic reactions	13 (19.1%)	10.6;30.5	4 (11.8%)	3.3;27.5
Fever	2 (2.9%)	0.4;10.2	0	0.0;10.3
Headache	6 (8.8%)	3.3;18.2	1 (2.9%)	0.1;15.3
Malaise	8 (11.8%)	5.2;21.9	2 (5.9%)	0.7;19.7
Myalgia	7 (10.3%)	4.2;20.1	3 (8.8%)	1.9;23.7
Arthralgia	2 (2.9%)	0.4;10.2	0	0.0;10.3
Unsolicited adverse events*
Any unsolicited adverse event	17 (25.0%)	15.3;37.0	2 (5.9%)	0.7;19.7
Infections and infestations	1 (1.5%)	0.0;7.9	1 (2.9%)	0.1;15.3
Musculoskeletal and connective tissue disorders	2 (2.9%)	0.4;10.2	0	—
General disorders and administration site conditions	14 (20.6%)	11.7;32.1	1 (2.9%)	0.1;15.3
Injury, poisoning, and procedural complications	1 (1.5%)	0;7.9	0	—

N = number of participants in safety analysis set.

n = number of participants with available data for the event.

95% CI = 95% confidence interval.

^*Adverse events are presented by System Organ Class (SOC). SOCs follow the structural hierarchy of the MedDRA (Medical Dictionary for Regulatory Activities) terminology, developed by the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). In this study, the coding of adverse events and reactions was in accordance with MedDRA version 16.0.