According to Deepta Bhattacharya, PhD, an immunologist at the College of Medicine – Tucson, the virus must overcome "backup layer after backup layer" of defenses. So even if a virus continues to spread through a person's body, "each stage it has to get past takes a bigger chunk" out of it, Bhattacharya said.

It’s true that some people have tested positive for the coronavirus even after getting a vaccine, but that is no indication the vaccines don’t work. On the contrary, public health experts say the evidence is overwhelming that the shots dramatically reduce your chances of severe illness and death. “I lose infinitely more sleep over the fact that we have such large numbers of unvaccinated people who are at a tremendous risk of developing severe disease,” Janko Nikolich-Žugich, MD, PhD, an immunologist and professor of medicine at the College of Medicine – Tucson, told NBC News. “We shouldn’t be complacent or cavalier about it, but it pales in comparison to the question of how we get as many people as possible vaccinated.”

Public health experts say the evidence is overwhelming that the shots are doing exactly what they are supposed to do. They dramatically reduce your chances of severe illness and death. “I lose infinitely more sleep over the fact that we have such large numbers of unvaccinated people who are at a tremendous risk of developing severe disease,” Janko Nikolich-Žugich, MD, PhD, an immunologist and professor of medicine at the College of Medicine – Tucson, told NBC News. “We shouldn’t be complacent or cavalier about it, but it pales in comparison to the question of how we get as many people as possible vaccinated.”

The CDC reversed its mask guidance Tuesday and is now recommending the use of masks indoors in areas of high or substantial transmission, as well as masking for everyone in K-12 schools. "Two things with the delta variant: One is that it's much more infectious than previous variants. And two, vaccinated people can actually spread it to other people," said Shad Marvasti, MD, director of public health and prevention at the College of Medicine – Phoenix.

Dr. Lorraine Martin-Plank says the pandemic revealed multiple improvements that can be made to help older adults in nursing homes stay engaged and healthy.

Banner Health is now requiring all employees to receive the COVID-19 vaccine by Nov. 1, 2021.

Messy bedrooms can trigger feelings of alertness and anxiety, so Salma Patel, MD, a sleep medicine specialist at the College of Medicine – Tucson, recommends keeping your sleep space as clean and organized as possible. “Piles of unfinished laundry, visible to-do lists, and other forms of clutter can be stimulating,” she warns. “They remind you of work that needs to be done, which can make it harder to fall asleep.”

With the rise of the über-transmissible delta variant, experts are saying you’re either going to get vaccinated, or going to get the coronavirus. For some people—a decent number of us, actually—it’s going to be both. Coronavirus infections are happening among vaccinated people. To understand the anatomy of a breakthrough case, it’s helpful to think of the human body as a castle. Deepta Bhattacharya, PhD, an immunologist at the College of Medicine – Tucson, compares immunization to reinforcing such a stronghold against assault.

A report by Joe Gerald, MD, PhD, associate professor of public health policy and management at the Mel and Enid Zuckerman College of Public Health, looking at the week ending on July 11, found cases began to show an increase in numbers for the fifth consecutive week — increases that come on the heels of state lawmakers and Gov. Doug Ducey restricting what schools, businesses and local governments can do to curb the spread of the pandemic.