Table 1.
Demographics of Normal and Low Responder Sub-cohorts.
| Cohort | Dryvax cohort | ACAM cohort | |||||
|---|---|---|---|---|---|---|---|
| Demographic Category | Subcategory | Low Responders1 n = 19 | Normal Responders1 n = 1,052 | p-value | Low Responders1 n = 38 | Normal Responders1 n = 956 | p-value |
| Gender | % Female | 5.3% | 26.6% | 0.04 | 10.5% | 10.3% | 1.0 |
| Race | Asian/American Indian | 0.0% | 7.0% | 0.5 | 0% | 4.6% | 0.3 |
| African American | 10.5% | 17.5% | 23.7% | 11.8% | |||
| White | 57.9% | 53.1% | 73.7% | 79.1% | |||
| More than one race | 15.8% | 8.0% | 0.0% | 1.5% | |||
| Other/Do not know | 15.8% | 14.4% | 2.6% | 3.0% | |||
| Ethnicity | Not Hispanic | 63.2% | 74.6% | 0.2 | 78.9% | 81.7% | 0.7 |
| Hispanic | 26.3% | 21.3% | 21.1% | 17.2% | |||
| Do not know | 10.5% | 4.1% | 0% | 1.2% | |||
| Age (years) | 19–21 | 15.8% | 22.7% | 0.7 | 7.9% | 15.2% | 0.2 |
| 22–23 | 36.8% | 24.0% | 34.2% | 27.8% | |||
| 24–27 | 26.3% | 28.3% | 23.7% | 33.5% | |||
| 28–40 | 21.1% | 25.0% | 34.2% | 23.5% | |||
| Time Since Vaccination (months) | 1–8 | 36.8% | 24.0% | 0.3 | 0% | 6.5% | 0.1 |
| 9–14 | 10.5% | 25.6% | 73.7% | 59.5% | |||
| 15–33 | 31.6% | 25.9% | 21.1% | 18.8% | |||
| 34–48 | 21.1% | 24.5% | 5.3% | 15.2% | |||
1
The low responder group includes all subjects with neutralizing antibody titers less than 1:32. The remaining subjects are classified as normal responders
2
Fisher’s exact test. Statistically significant differences are shown in bold font.