| in the usa | 3 | location |
| after administration | 2 | temporal |
| in certain susceptible individuals | 2 | other |
| vaccine → cause → polio | 8 |
| vaccine → caused → polio | 3 |
| negative | neutral | positive |
| 0.628 | 0.316 | 0.056 |
| Raw frequency | 11 |
| Normalized frequency | 0.177 |
| Modifier score | 0.500 |
| Perplexity | 430.359 |