PHILADELPHIA , Sept. 22, 2025 /PRNewswire/ -- National plaintiffs' law firm Berger Montague PC  announces a class action lawsuit against Altimmune Inc. (NASDAQ: ALT) ("Altimmune" or the "Company") on behalf of investors who purchased or otherwise acquired publicly traded securities of Altimmune between August 10, 2023 through June 25, 2025 (the "Class Period"). ...