First vaccine approval under the FDA Animal Rule

The US Food and Drug Administration's Animal Rule was established to facilitate licensure of new products for life-threatening conditions when traditional efficacy trials in humans are unethical or impractical. In November, 2015 BioThrax became the first vaccine to receive approval for a new indication via this pathway. The basis for this approval and use of Animal Rule or other non-traditional approval pathways for licensure of vaccines for serious conditions are discussed.