considered to have high covid transmission. one of our medical experts says the delta variant is like nothing he's ever seen before. we'll speak to him in a minute. it is so contagious that it's impacting some people who are fully vaccinated, and it's pushing frontline healthcare workers to the brink. cnn's athena jones has been tracking the latest for us across the country. athena, what's happening on the ground? >> reporter: hi, alisyn. it wasn't supposed to be this way. the vaccines approved months ago were supposed to help prevent another summer covid surge like we're seeing all across the country, but the pace of daily vaccinations is at its lowest point since january, and once again we're hearing heartbreaking stories from healthcare workers who are struggling to save the lives of people who refuse the protection the vaccines offer. the biggest public health crisis in a century is threatening to get a lot worse. as the more contagious delta variant super charges covid-19's spread. especially in places with low vaccination rates. >> it just seems like we're just