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# Guidance on Smallpox Drug Development
- URL: https://www.fdaweb.com/guidance-on-smallpox-drug-development/
- Published: 2019-11-15T12:00:00.000Z
- Updated: 2026-09-14T15:53:14.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5145518

FDA has issued a final guidance entitled “[Smallpox (Variola Virus) Infection: Developing Drugs for Treatment or Prevention](http://email.prnewswire.com/wf/click?upn=zySGXW1QLHU8t7wSbPI8iADmwAaKTbie2jeFmcdktocjGBInqn2pWYBITn6OYsXkxjvMo-2Bs8rbhgN-2BIVgWSbDI968K7o4Z5Mwqq-2Fh8HKA97ZTCq0vJnzzKzC0mSTkduFJhQvcyhOkorQUzcNAySonnHpsZek2CyvujA78Z083Ce615Th4E1rErKm-2F6KmAXNcJ-2Fpb7OqYnRUs35yHvojOT69edNftqU-2BipUvGKmHW5kBmHIpbMncViXAnZp7-2BwOHXKPWMdHGfawrEqEht24dWaA-3D-3D%5FnE9rxSXA5G4kxsTVkgv43tTJnmhvULg8vMtvbdZHwXEle6c6tqdvw12Z3skft0RuFA9rFrd4F4AZPHxbYCI2zahIg2js-2FTHCcs2Qwlb0DfyMLzm2461l7iI7GxQsOkhGqbfvG6E6izjlSedE-2Flygfx7OdUJqbKYs-2BZ8viYtJPSvkNi6TSWNm6yjlP7YkPnFPcUa-2FoOwoWkjEAUaqDJw1lJ4kuSMesNRjYLp289sn85rn1ESiZWhnAAIXjIKU-2FYr7vsnJHk-2BHppx0pW5WezF-2F7LMXi1T2F6GU6bMlnu3WktM11WAYVFAXf-2BIF04gLE7ExdkeiN-2BmnZFnYhQkLRS8ClFO-2BCk2o9QbysCO3SSw1VYU-3D&ref=fdaweb.com)” to assist drug manufacturers designing studies to evaluate safety and efficacy of such drugs. The agency notes that smallpox was declared eradicated in 1980, but “concerns exist that it could remain in unknown locations or used as a biological weapon. The document clarifies the recommended immunological characterization of animals for key studies. Clinical efficacy trials of drugs for treating or preventing smallpox are not feasible and challenge studies in healthy subjects are unethical; therefore, drugs for these indications should be developed and approved under the regulations commonly referred to as the Animal Rule (21 CFR part 314, subpart I, for drugs and 21 CFR part 601, subpart H, for biologics),” FDA says.