You should read more of your own links.
Walensky was referring to a new CDC study of nearly 4,000 front-line workers, some vaccinated and some not, who tested themselves weekly for COVID-19 infections between December and March.
Among fully vaccinated people in the study, there were only three "break-through" COVID-19 infections detected. In stark contrast, unvaccinated participants in the study logged 161 COVID-19 cases.
In other words, two shots of Pfizer or Moderna's vaccines, followed by two full weeks for them to take effect, nearly zeroed out all detectable infections — including asymptomatic ones.
The CDC later walked back Walensky's comments in part, telling the New York Times that the evidence "isn't clear" and that the director was "speaking broadly."
"We hope that within the next five or so months we'll be able to answer the very important question about whether vaccinated people get infected asymptomatically, and if they do, do they transmit the infection to others," Dr. Anthony Fauci, the nation's top infectious-disease expert, said at a White House COVID-19 task-force briefing on Friday.
The CDC clarified her statements according to your own link and when put into context weren't nearly as aggregious as you tried to pretend they were.