Public health officials were caught off-guard by the sudden outbreak of COVID-19 cases caused by the delta variant, Scott Gottlieb told reporters on Thursday.

Gottlieb, the former Food and Drug Administration Chief (FDA), further explained that he thinks a peak is going to occur sooner rather than later.

"I think what you're seeing right now is the endgame, is a very big wave of infection in the summertime with a...much more transmissible variant than we thought we'd be dealing with, earlier than we thought we'd be dealing with, because the variant became prevalent far sooner than we expected," he said.

Citing low vaccination rates in select populations as a factor health officials didn't anticipate, he further forecasted a reimplementation of public health protocols as schools and workplaces try to reopen.

"There might be other things you do that actually achieve more risk reduction than the masks in the setting of a much more contagious variant where we know there's going to be spread even with masks," Gottlieb added.

He further expressed surprise at the Centers for Disease Control and Prevention (CDC) for not releasing any models projecting the delta variant's potential path, but estimated that there are more infections than are currently known.

Based on the known trajectory, however, Gottlieb added that the delta outbreak could peak around late August and into early September. 

The delta variant's spikes along states like Arkansas, Florida, Missouri, and Louisiana, and other southwestern municipalities have led to a 171 percent increase in new COVID-19 infections over the past two weeks, with corresponding increases in hospitalizations and deaths.

(With input from agencies)