Do we need the vaccines?

Pandemics have a beginning, a peak and an end, often in the form of a normal curve. If you start vaccinating people at the top of the normal curve, it may look like it is the vaccines that are causing the pandemic to end.  A safe vaccine in the beginning of a pandemic may make sense. 

An unsafe vaccine at the end is not as good.

Normal distribution curve

Below is a typical curve from CDC for an infection