STAT reports:

There is growing concern that the Food and Drug Administration, under political pressure, could approve a Covid-19 vaccine before it has robust safety and efficacy data.

The consequences of such a decision could be significant, particularly if the vaccine is ultimately shown to be less effective than early data suggest. But an approval before the completion of large, Phase 3 trials does not have to be problematic. Experts aren’t ruling out the possibility that a vaccine could be cleared this fall if it is very effective.

“There are mechanisms by which products that have a good amount of data can be made available in a controlled way,” said Natalie Dean, an assistant professor of biostatistics at the University of Florida who specializes in vaccine study design.

But Dean also sees risks.

“If you make a decision based on promising but not convincing data, and then you discontinue your randomization,” she said, “you discontinue your evidence-generating process. You can never go backward. You can never go back and generate your evidence.”

Here is how a fast approval might play out, if all goes well — and some warning signs that a science-based process is not being followed. [Continue reading…]