So those people aren't presenting for testing," added Gottlieb, who serves on the board of Covid vaccine maker Pfizer.
According to a CNBC analysis of Johns Hopkins University data, the weekly average of new daily Covid infections in the U.S.As recently as July 5, the nation's seven-day average of new daily infections was just below 12,000.
"Our ascertainment— the percentage of people who are presenting for testing and actually getting recorded— is quite low right now, so this infectious wave must be far more pervasive than what we're detecting, which means we're further into it than what we believe," Gottlieb said.