retweeted a claim that his own CDC was lying about COVID-19?

On July 13, 2020, Trump retweeted former game show host Chuck Woolery, who pushed to reopen schools amid record new cases of COVID-19. He alleged that scientific evidence pointed to the move, and that Democrats, Media, the CDC, and “our Doctors” had been lying about the disease.

Tweets from former game show host Chuck Woolery that were retweeted by the president of the United States.
Trump retweets former game show host Chuck Woolery, on the morning of Jul 13, 2020.

When asked if endorsing comments that doubted his own Center for Disease Control would be confusing to the public, Trump replied,

I didn’t make a comment. I reposted a tweet that a lot of people feel. But all I am doing is making a comment. I’m just putting somebody’s voice out there. There are many voices. There are many people that think we shouldn’t do this kind of testing, because all we do, it’s a trap.

Three days later, Woolery deleted his Twitter account upon learning that his son tested positive for COVID-19.

On the day of the retweet, the United States totaled 3,483,584 cases and 120,004 deaths.

The Hill – Trump retweets game show host who said CDC is lying about coronavirus to hurt him politically
The Hill – Game show host retweeted by Trump deletes his account after announcing his son has coronavirus

The Baltimore Sun – After Trump retweets game show host saying CDC and doctors are lying, coronavirus task force pushes back: ‘None of us lie’
Deadline – Donald Trump, In CBS News Interview, Defends His Retweet Of Chuck Woolery’s Claim That CDC Officials Are Lying About COVID-19
Worldometer – Coronavirus Cases, United States