May Sponsors choose to use the Animal Rule path to licensure over more traditional pathways?
No, the FDA will only consider vaccine licensure under the Animal Rule (21 CFR 314 Subpart I or 601 Subpart H) when human efficacy studies are not possible for ethical reasons or because field studies to assess efficacy are not feasible. If licensure is feasible by field trials or by using the Accelerated Approval regulations (21 CFR 314 Subpart H or 21 CFR 601 Subpart X), the Animal Rule would not be pursued.