Indeed it doesn’t, and in more ways than former FDA commissioner Scott Gottlieb lays out here. Gottlieb tells CNBC’s Squawk Box that the new guidance doesn’t appear based on any real evidentiary shift, and is also doomed to failure anyway. Masks will have a “negligible impact” on the spread of the Delta variant of COVID-19, and the emphasis should really be elsewhere:

.@ScottGottliebMD weighs in on the CDC’s updated mask guidance. pic.twitter.com/7H7bCEYm0w

— CNBC (@CNBC) July 28, 2021

Gottlieb, who said that he expects the surge in coronavirus cases from the Delta variant to dissipate in two to three weeks, noted that vaccinated people “just need to be mindful” that they can still transmit the virus — especially variants with high viral loads like Delta.

“Much more prudent guidance to people would be that if you are vaccinated in a high prevalence area, in contact with virus, you think you might have the virus because you have mild symptoms, be prudent, get tested, maybe wear a mask especially if you are around a vulnerable person,” Gottlieb said.

“Whether or not that should then translate to general guidance for the entire population, I don’t think that that’s the case. I don’t think we’re going to get enough bang for our buck by telling vaccinated people that they have to wear masks at all times to make it worth our while,” he added.

Not only will it not get “bang for the buck,” it comes with its own cost. By demanding that the vaccinated wear masks, the CDC erodes the incentive among the hesitant to get the vaccine. That’s entirely counterproductive, as vaccines are the only effective way to stop the spread, even of the Delta variant.

Gottlieb mentions the viral-load findings as significant, though, echoing Anthony Fauci this morning in explaining that they are a “game changer.” Are they, though?

My hunch was right. $20 they didn’t culture that “viral load” to see if it was infectious. pic.twitter.com/SZmRw1nrhd

— Aaron Ginn (@aginnt) July 28, 2021

Ginn raises a very good question. Nasopharynx tests for COVID have had difficulties distinguishing between viral particles that can cause infection and inert viral particles that are being shed by immune hosts. It usually takes culturing to determine the difference, and it’s still unclear whether their research has actually included that step. One would expect, however, that if culturing showed that the vaccinated can shed live viral particles in enough abundance to infect other people, the CDC would have made that argument explicit.

But let’s say for the sake of argument that culturing shows these to be live viral particles capable of spreading the Delta variant. What exactly does that mean for the vaccinated who are being cajoled/ordered to mask up? We once again return to the CDC’s data on breakthrough infections and even on cases in general. If the 163 million-plus vaccinated are truly vectors for the spread of Delta and are at risk themselves for infection, we’d be seeing vastly higher rates of infection, hospitalization, and deaths. Instead, hospitalizations and deaths among the vaccinated account for less than 1% of the vaccinated population. Even after a couple of months of the Delta variant being dominant, the three vaccines approved for emergency use are proving 99%-plus effective against both serious complications and death. That’s better than most vaccines for diseases spread by close human proximity, I’d bet.

And if the only risk for the vaccinated is that they could pass it along to the unvaccinated, we’re back at the question of who should carry the burden of that risk. Should that fall by mandate onto the vaccinated, who have taken the (extremely small) risk of the vaccine, or should it fall on those who haven’t or won’t get vaccinated? At this point, anyone above 12 years of age who wants the vaccine has all-but-instant access to it. Those who accept the risk of remaining unvaccinated shouldn’t expect everyone else to indemnify them from the consequences of that choice. And the CDC should be working on getting more of them to choose the vaccine rather than making it easier for them to avoid it.

Gottlieb’s advice makes much more sense. If you think you’ve been exposed as a vaccinated person, then take caution around at-risk individuals in your orbit and perhaps think about wearing an N95 mask if in close proximity to them. Otherwise, there’s really no point in masking up once you’ve been fully vaccinated, and the data from our 163-million-plus sample makes that crystal clear.