What happened Shares of Altimmune (NASDAQ: ALT) were flying 16.7% higher as of 11:27 a.m. EDT on Monday. The big jump came after the company and the University of Alabama at Birmingham (UAB) reported positive preclinical results for intranasal COVID-19 vaccine candidate AdCOVID. So what Altimmune and UAB reported that mice receiving AdCOVID demonstrated a "strong systemic antibody response" 14 days after receiving a single intranasal dose of the vaccine candidate. Lead investigator and UAB professor Dr. Frances Lund said, "Stimulation of immunity at this level just 14 days after a single dose is impressive for any vaccine, and is particularly notable for a potential coronavirus vaccine." Image source: Getty Images. It's important to keep in mind, though, that success in preclinical testing doesn't always carry over into clinical studies. Human responses to vaccine candidates can be much different than the responses in mice. Still, the preclinical results were great news for Altimmune. The biotech doesn't have any approved products on the market. Its lead pipeline candidate, intranasal flu vaccine NasoVAX, is ready for phase 2b testing. However, Altimmune is seeking a partner to advance the clinical development of the vaccine candidate. Now what Another major catalyst for the biotech stock could be on the way relatively soon. Altimmune plans to begin a phase 1 study of AdCOVID in the fourth quarter of 2020. 10 stocks we like better than ALTIMMUNE INCWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and ALTIMMUNE INC wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 2, 2020 Keith Speights has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source