AstraZeneca-Oxford Vaccine Reduces Transmission Rates. Biden Admin's Strategy Of Getting More People The First Shot Vindicated?

Mostly good news in this story, it seems (good news being permissible again now that bad Orange Man is gone). For awhile we were hearing these weird reports about the vaccines not reducing transmission rates--but that just seemed too crazy to be true. It always seemed plausible that it might be more important to get more people one shot than fewer people two, so there's no real surprise there--at least from the perspective of a layperson.  I wonder whether it might be better to get a different vaccine the second time.