Dr. Vinay Prasad, the controversial critic of the US Food and Drug Administration who took a top role at the regulatory agency in May, has resigned less than three months into the job.

Dr. Vinay Prasad, the chief scientific officer at the Food and Drug Administration, has resigned after only three months in the position.

The Food and Drug Administration's polarizing vaccine chief is leaving the agency after a brief tenure that drew the ire of biotech executives, patient groups and conservative allies of President Donald Trump.