Table 1.
Baseline Demographics and Inclusion/Exclusion Criteriaa
| Dryvax (n = 29) | LC16m8 (n = 125) | All Groups (n = 154) | P value | |
| Gender | ||||
| Female | 13 (45%) | 44 (35%) | 57 (37%) | .39 |
| Male | 16 (55%) | 81 (65%) | 97 (97%) | |
| Ethnicity | ||||
| Hispanic | 2 (7%) | 3 (2%) | 5 (3%) | .24 |
| Non-Hispanic | 27 (93%) | 122 (98%) | 149 (97%) | |
| Race | ||||
| Native American | 0 | 2 (2%) | 2 (1%) | .84 |
| Asian | 2 (7%) | 7 (6%) | 9 (6%) | |
| African American | 1 (3%) | 2 (2%) | 3 (2%) | |
| Pacific Islander | 0 | 1 (1%) | 1 (1%) | |
| Caucasian | 26 (90%) | 110 (88%) | 136 (88%) | |
| Multiracial | 0 | 3 (2%) | 3 (2%) | |
| Age, y | ||||
| Mean (SD) | 22.7 (3.5) | 23.4 (4.0) | 23.3 (3.9) | .56 |
| Median | 21.6 | 22.4 | 22.2 | |
| Range | 18.8–32.6 | 18.1–34.0 | 18.1–34.0 |
Percentages are calculated from the number of volunteers in each vaccine group.
Inclusion criteria: Participants were 18–34-year-old individuals (year of birth, 1971–1987) with no history of smallpox vaccination, and in good health as ascertained by medical history, clinical assessment, and baseline blood chemistries including hepatic function tests; were willing to refrain from any blood donations until vaccination scab was gone; and had negative serology for hepatitis B and C and human immunodeficiency virus, negative urine glucose, and a normal ECG. Exclusion critera included active or past history of atopic dermatitis, eczema, or immunosuppression; known cardiac disease or 3 or more cardiac risk factors; known allergies to study materials and vaccine components; females who were pregnant or not willing to use birth control or were breastfeeding; frequent contact or sharing of linen with someone who was pregnant or breastfeeding or had atopic dermatitis or eczema; Darier disease or contact with someone with Darier disease; frequent contact with an infant < 1 year of age; history of exuberant keloid formation; issues that would preclude compliance with protocol or would be exacerbated by the protocol such as psychiatric illness; recent vaccinations either before or after smallpox vaccination (live within 30 days, killed within 2 weeks); military service prior to 1989; receipt of blood products within 60 days prior to screening; or participation in another experimental drug protocol.