Still, now that Biden has shown he's willing to export the vaccine the U.S. isn't using, the obvious next question is when he'll allow exports of the ones it is: Pfizer, Moderna and Johnson & Johnson. What to watch: Nearly every U.S. adult who wants a vaccine will likely have had one within the next two to three weeks, Axios' Caitlin Owens reports. And as demand begins to wane, supply should continue to ramp up. Pfizer, Moderna, J&J and AstraZeneca still owe the U.S. hundreds of millions of doses (more still if Biden exercises additional purchase options). Biden will face international pressure and public health imperatives to share those doses with the world. He has said that he hopes to do so once the U.S. has a "surplus" but offered no clarity as to what qualifies as a surplus or where the doses will go.