I don't have any evidence that the CDC was deliberately withholding information (not to say it doesn't exist), but I do have evidence that medical leaders have felt it okay to lie to the public with regards to covid.
> In the pandemic’s early days, Dr. Fauci tended to cite the same 60 to 70 percent... And last week, in an interview with CNBC News, he said “75, 80, 85 percent” and “75 to 80-plus percent.”
> In a telephone interview the next day, Dr. Fauci acknowledged that he had slowly but deliberately been moving the goal posts. He is doing so, he said, partly based on new science, and partly on his gut feeling that the country is finally ready to hear what he really thinks.
> “When polls said only about half of all Americans would take a vaccine, I was saying herd immunity would take 70 to 75 percent,” Dr. Fauci said. “Then, when newer surveys said 60 percent or more would take it, I thought, ‘I can nudge this up a bit,’ so I went to 80, 85.”
https://www.nytimes.com/2020/12/24/health/herd-immunity-covi...