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Viral exposure strain and route for most participants of the respective vaccine efficacy designs discussed in this article
| Unintended natural exposure | Challenge |
||
|---|---|---|---|
| Intranasal inoculation | Human interaction | ||
| Defined (and potentially GMP) strain | / | A conventional challenge, that is, one with exposure to a defined strain through intranasal virus inoculation (CDI) | / |
| Natural strain | Standard field trials (FTs) | / | Challenge with exposure through human interaction to a natural strain (CNH) |
