[GrumpyOldMan]

Originally Posted by golfing eagles

OK, I'll bite.

Here is the part of the article that is essentially a disclaimer:

"The findings in this report are subject to at least four limitations. First, data from this report are insufficient to draw conclusions about the effectiveness of COVID-19 vaccines against SARS-CoV-2, including the Delta variant, during this outbreak. As population-level vaccination coverage increases, vaccinated persons are likely to represent a larger proportion of COVID-19 cases. Second, asymptomatic breakthrough infections might be underrepresented because of detection bias. Third, demographics of cases likely reflect those of attendees at the public gatherings, as events were marketed to adult male participants; further study is underway to identify other population characteristics among cases, such as additional demographic characteristics and underlying health conditions including immunocompromising conditions.*** MA DPH, CDC, and affected jurisdictions are collaborating in this response; MA DPH is conducting additional case investigations, obtaining samples for genomic sequencing, and linking case information with laboratory data and vaccination history. Finally, Ct values obtained with SARS-CoV-2 qualitative RT-PCR diagnostic tests might provide a crude correlation to the amount of virus present in a sample and can also be affected by factors other than viral load.††† Although the assay used in this investigation was not validated to provide quantitative results, there was no significant difference between the Ct values of samples collected from breakthrough cases and the other cases. This might mean that the viral load of vaccinated and unvaccinated persons infected with SARS-CoV-2 is also similar. However, microbiological studies are required to confirm these findings."

And I would add a 5th limitation----how many of those vaccinated were 5+ months out from their vaccine and possibly starting to lose immunity

And maybe a 6th---how many had the J&J vaccine which is thought to be less effective.

So the jury is still out, I'm not convinced that this single report from a single county can be extrapolated to the whole country. Maybe it can, but that is yet to be proven. What happens is this info gets reported to the CDC and then the question "so what are you going to do now?" arises. So they make a very conservative recommendation. Just as expected'

Oh, wait, that wasn't "spin and out-of-context quoting and off-topic misinformation.". So sorry to disappoint

Very good point. I do think the CDCs initial disclaimer about the lack of quality data encompasses your suggestions, but that does not reduce what you said.

As I said in the OP - Bad News. Not yet definitive. But no "good news" ... sigh. At least part of the bad news is that we are not collecting enough data to make good decisions.