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| H5N1 | |
|---|---|
| • New influenza A sub‐type: haemagglutinin (H) unrelated to immediate (pre‐pandemic) predecessor | ✓ |
| • Little or no pre‐existing population immunity | ✓ |
| • Causes significant clinical illness | ✓ |
| • Efficient person‐to‐person spread | X |
