(also replicated by the recent NBA study that I failed to bookmark, which also found that the Ct levels were similar with delta and prior variants, including old-school D614G although the average for delta was slightly lower but not within the statistical power of the study)
That means that while mRNA loads are similar in breakthrough infections they're composed of more viral debris and they clear faster. That suggests they're less transmissible.
During Alpha, 80% of breakthrough infection is Israel did not transmit in social settings:
There's no evidence that is free from massive confounding factors that delta is really that much of a game changer in vaccinated individuals. Its biggest effects is on pushing the herd immunity threshold across the population near enough to 100% as not to matter and for being twice as bad for unvaccinated individuals.
The reasonable evidence is still that vaccines work and are effective and safe and the best way to end the pandemic, and that delta is still largely transmitting and killing people through the unvaccinated population.
>The reasonable evidence is still that vaccines work and are effective and safe and the best way to end the pandemic, and that delta is still largely transmitting and killing people through the unvaccinated population.
the publicly available numbers that i mentioned (from MA, Israel, Singapore, UK) show that the chances of vaccinated to get infected is 25% of that of unvaccinated (400 out of 1400 with 65% vaccination rate, and that is without paying attention to an obvious fact that breakthrough infections are heavily undercounted due to vaccine softening the disease symptoms). The 25% chances is absolutely too big to speak about any meaningful effect on slowing the spread. Such conclusion clearly comes from basic statistical arithmetic, as well as from seasonal flu vaccine experience where the efficacy is in the same ballpark.
https://www.medrxiv.org/content/10.1101/2021.07.31.21261387v...
"We find no difference in viral loads when comparing unvaccinated individuals to those who have vaccine “breakthrough” infections. "
>that high level of virus lasts only three to four days compared with an unvaccinated person who could be contagious for up to 10 days
may be. Yet it is the first days what matter until one notices that s/he is ill.
And the article you cite has gems like this
>Cases of breakthrough infections among the vaccinated remain rare.
Where is for example in MA - with 65% vaccination rate - out of the 1400 new daily infections the 400+ are breakthrough :
https://www.nbcboston.com/news/coronavirus/mass-has-3098-new...
And there is similar data from highly vaccinated places like UK, Israel, Singapore.