Americans Are Highly Vaccinated Against Polio. Here's Why It Could Still Spread

CNN's Dr. Sanjay Gupta speaks to registered nurse Kate Carleton about her efforts to prepare schoolchildren to treat injuries suffered in a mass shooting.

These senior citizens have waited on the phone for hours, driven miles, set-up work stations so they could get a Covid-19 vaccine appointment. See who was able to get one.

The global fertility rate has fallen from 5 births per woman in 1950 to 2.3 in 2021 - and even lower in the U. S., partly due to the cost of child-rearing and shifts in priorities. But "falling population and an elderly or aging population puts a lot of fiscal and economic pressures on society," says Economics Professor Melissa Kearney.

Independent presidential candidate Robert F. Kennedy Jr. told The New York Times he experienced a series of health issues in recent years, including an abnormality that he said was caused by a worm that entered his brain and then died. CNN chief medical correspondent Dr. Sanjay Gupta explains how this could have happened.

Americans' mental health issues are not identified and treated as readily as physical symptoms, especially among children - in part due to a shortage of clinicians. "We're looking for ways to integrate mental health into settings where children and families are every day," says Dr. Tami Benton, President of The American Academy of Child and Adolescent Psychiatry.

Mayor Donna Deegan speaks with CNN's Jake Tapper