On May 13th 2021 the CDC changed its guidance regarding the behavior of vaccinated people, with it effectively killing COVID and returning to where they started.
How it Started
Beginning with their guidance issued last year, on April 3rd 2020, the CDC adopted a position that stood in stark contrast to both the consensus of the scientific community along with years of their own prior guidance: They claimed surgical and cloth masks help slow the spread of respiratory viruses like COVID-19, and they recommended people wear them in community settings. That recommendation stood, even increasing to a recommendation of double masking on February 10th 2021. All this in spite of mountains of evidence, both from the US and around the world, that masks have no measurable effect on the trajectory of COVID.
Unsurprisingly there was a massive backlash against the CDC's new recommendations from the very Twitter snowflakes who have been screaming "SCIENCE!!!" for the last 14 months. They claimed the CDC was acting irrationally, that not enough people have been vaccinated, that people would lie about their vaccine status, that cases will spike, and so on. Ironically, of course, none of these people had any logical or scientific reasoning behind these claims (except maybe the honesty part), but they made the claims nonetheless.
The CDC had to know this backlash would come. They also had to know the most popular criticism-positioned-as-a-question would be "but how do we know who's vaccinated?", because with HIPAA and without COVID passports, there is no way to know for certain if someone were being honest about their vaccination status. At the same time the CDC was also very aware that no State that had removed mask mandates and other nonpharmaceutical interventions had seen a spike in cases.
The Reality and the Opportunity
The CDC couldn't avoid reality forever. While they understood people would be upset with the change in guidance, they had put themselves in this indefensible position by claiming masks mattered while having no data to support that position and no way to answer for all the data that supported the other side. If the CDC truly believed masks did the things they had claimed for the last year, there's no way they should have recommended their removal.
Instead, the CDC took advantage of an opportunity to return to their pre-2020 position on masking in community settings and get back on the correct side of the science. Given what we've all seen in States that have removed mandates, they know that cases will continue their downward trend. It was an expert political play to fix a mistake without having to admit it by an organization that's supposed to be about science, not politics. Kudos to the CDC. Better late than never.