Literally two paragraphs before your quoted text:

> Dr. Walensky spoke broadly ... “It’s possible that some people who are fully vaccinated could get COVID-19. The evidence isn’t clear whether they can spread the virus to others.”

Seems like they arn't saying you cannot get it, but that you are LESS LIKELY to spread it. Which, if Covid was spread via coughing/sneezing, and the vaccine reduces those symptoms, would be a logical next step. She also hedged multiple times, stating that this is just what the initial data is saying, and not a full-throated promise.