April 11, 2019 Vipin Garg Chief Executive Officer Altimmune, Inc. 910 Clopper Road, Suite 201S Gaithersburg, MD Re: Altimmune, Inc. Registration Statement on Form S-3 Filed April 4, 2019 File No. 333-230723 Dear Dr. Garg: 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 Joe McCann at 202-551-6262 with any questions. Sincerely, Division of Corporation Finance Office of Healthcare & Insurance