INOVIO announced that several volunteers have been dosed with its DNA-based, intradermal Ebola vaccine candidate, INO-4201, as part of a randomized, placebo-controlled, Phase 1b clinical trial (NCT04906629). The trial will assess whether INO-4201 can be used as a booster in healthy volunteers previously vaccinated with rVSV-ZEBOV (Ervebo?1), an FDA- and EMA-approved viral-based vector Ebola vaccine. It follows INOVIO's pre-clinical and Phase 1 trials which suggested to investigators that INO-4201 was well-tolerated and resulted in 100% seroconversion after two doses. Investigators plan to recruit approximately 50 healthy volunteers to participate in the clinical trial. The trial will evaluate the safety, tolerability, and immunogenicity of INO-4201 in healthy adult volunteers who previously received a single intramuscular injection of rVSV-ZEBOV (Ervebo). Ervebo is approved by the U.S. Food and Drug Administration (FDA) for the prevention of disease caused by Zaire ebolavirus in individuals 18 years of age and older as a single dose administration. Ervebo is a replication-competent, live, attenuated recombinant vesicular stomatitis virus (rVSV) -based vaccine. Trial participants will be randomized to either INO-4201 or placebo (4:1 ratio) and will receive an intradermal injection followed by electroporation using INOVIO's CELLECTRA? 2000 smart delivery device. The primary outcome measures include the incidence of adverse events related to INO-4201 from day 0 to 14, and levels of antibodies that bind to Ebola virus surface glycoprotein antigen four weeks after injection. The trial is being coordinated by GuardRX, a non-profit organization whose goal is to spur development of and access to life-saving therapeutics. Its sponsor is the Geneva University Hospitals, which conducted one of the first randomized trials testing the Ervebo vaccine in 2014. The trial is funded by the U.S. Defense Advanced Research Projects Agency (DARPA). The information herein does not necessarily reflect the position or the policy of the U.S. Government, and no official endorsement should be inferred. INO-4201 is composed of a precisely designed DNA plasmid that is injected intradermally followed by electroporation using a proprietary smart device, which delivers the DNA plasmid directly into cells in the body and is intended to produce a well-tolerated immune response. As one of the only nucleic acid-based vaccine candidates INO-4201 is stable at room temperature for more than a year, at 37?C for more than a month, has a five-year projected shelf life at normal refrigeration temperature and does not need to be frozen during transport or storage.