There wasn’t enough time for a full new trial, especially as the first phase was meant to be a trial in and of itself and was intended for crucial high risk ind

There wasn’t enough time for a full new trial, especially as the first phase was meant to be a trial in and of itself and was intended for crucial high risk individuals like healthcare workers. So the country had to rely on what data was available, which showed much better effectiveness against B.1351 from the Pfizer and J&J vaccines.