evidence: It is possible that one or more of the OWS vaccine candidates will become available for public use over the next several months. Four candidates have already advanced to Phase 3 trials, undergoing study in large groups of volunteers to determine their safety and efficacy. Under the most optimistic scenarios, initial trial results for at least one vaccine candidate could be available as early as the end of October. However, it is more likely results will start to become available later in the year or next year, and companies have said they would not start to pursue authorization until late November at the earliest. Typically, vaccines are approved through the FDA’s Biologic License Application (BLA) process, but during a public health emergency the FDA can grant an Emergency Use Authorization (EUA) for a vaccine even before full approval if certain criteria are met. Access through an EUA is accelerated compared to a BLA because the requirements are less stringent and vaccine use under an EUA could be more limited to specific target groups.