Janssen’s clinical trial tracked participants after they only got just one dose of its vaccine, a potentially sizable advantage. All other vaccines available or in late stage clinical trials require two doses—which complicates the logistics of distribution. On top of that, Janssen’s shot only requires regular refrigeration to be shipped and stored. Together, those two factors could make it significantly easier to quickly inoculate large swaths of the global population.
In a press conference, Janssen announced that it’d be reporting these data to the US Food and Drug Administration (FDA) within the coming week. Based on the regulatory agency’s review of the data, it could grant emergency use authorization, making it the third vaccine available in the US, behind the Moderna and the Pfizer-BioNTech vaccines. Here’s what we know, and don’t know, about the vaccine so far.