August 8, 2018 William Enright President and Chief Executive Officer Altimmune, Inc. 910 Clopper Road, Suite 201S Gaithersburg, Maryland 20878 Re: Altimmune, Inc. Registration Statement on Form S-1 Filed July 30, 2018 File No. 333-226441 Dear Mr. Enright: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Irene Paik at 202-551-6553 with any questions. Sincerely, Division of Corporation Finance Office of Healthcare & Insurance cc: Stuart Bressman, Esq. - Proskauer Rose LLP