Not the person you're responding to, but this is one of the more egregious examples that comes to mind, from the Director of the CDC herself:

"Our data from the CDC today suggests that vaccinated people do not carry the virus, don't get sick, and that it's not just in the clinical trials, but it's also in real-world data." ~Dr. Rochelle Wolensky[1]

This was a lie, and it was not only repeated but amplified by those in positions of authority up to and including the President of the United States.

[1] https://www.businessinsider.com/cdc-director-data-vaccinated...