however, the Delta variant is causing more 'breakthrough' cases, so it is prudent for everyone, including those who have been vaccinated, to wear masks indoors in locations with low vaccination rates and high case counts...all of this is to protect those who haven't been vaccinated yet. Once we get to a condition, nationally, that approaches, or exceeds, Vermont (67.6%) we'll all be the better for it...so, get vaccinated and wear your trusty mask when required...pretty simple plan for defeating COVID.
Parsing the degree of COVID transmission from breakthrough cases doesn't change the equation.