Shelby Detrick values the shots her four-year-old daughter Stella gets, including a shot for polio.
"I think vaccines are really important to help stop the spread of disease," she said.
Polio is one of more than a dozen vaccines the CDC recommends for children under 18.
The U.S. has immunized children against polio since the '50s. It's four shot doses given at two months, four months, six months to 18 months and between ages 4 to 6. Some states require only three doses.
Every state has laws requiring children to have their polio shot series to attend school.
"Once they receive those four injections, they're very likely immune for life," said Dr. Reginald Washington, chief medical officer of Presbyterian St Luke's Medical Center and the Rocky Mountain Hospital for Children.
It can be challenging for adults unsure if they've had their shots.
There is no national organization that maintains vaccination records. The only record out there is the one a person, or their parents or caregiver, have from that appointment. The doctor or clinic take a medical record then, too.
To track down Polio vaccine records, the CDC says to first ask a parent or caregiver if they kept them.
If that doesn't work, the CDC suggests checking baby books or high school records or a state's registry.
That can be time-dependent. For example, California's vaccine record registry didn't get information until the 90s and early 2000s. And not all providers participate.
Experts say if your doctor is retired, sometimes patient records are sent to a medical record storage company. That may cost a fee to get to.
"There's no downside if you're totally not aware of your status," Washington said.
Washington tells Newsy when in doubt, call your doctor to schedule a polio vaccine.
NEWSY'S LINDSEY THEIS: Even if someone gets two sets of their polio vaccinations, it's not going to have some horrible adverse effect?
DR. REGINALD WASHINGTON: That's absolutely correct. Because, remember, the the vaccine has killed the virus. So there's no way you can actually get polio from getting that injection.
New CDC findings show the polio virus has been in the wastewater of two New York counties as far back as April.
Only one case has been caught — A man who is now paralyzed. He was not vaccinated. The county he lives in has a polio vaccination rate that's nearly 20% below the state average and 33% below the national rate.
This is where herd immunity comes into play. In highly vaccinated communities — a school classroom, a neighborhood, a county — the polio virus can't spread it because it can't find a host. Even those unvaccinated are harder to get to.
That protection is much lower in a population with a lower vaccination rate because the immunity isn't there.