As family and friends gather this holiday season, there's a warning for new parents.

The CDC says cases of whooping cough or pertussis remain elevated this year.

In Kentucky this week, an unvaccinated infant died from the illness,

the third child to die of whooping cough in the state this year.

Other states across the country, including Texas, Florida, California,

and Oregon are also experiencing a surge of cases. Allie Rogan spoke with Dr. Lorne Walker,

a pediatric infectious disease specialist. Thank you so much for joining us. First of all,

can you just tell us what is whooping cough? What are the characteristic signs of it?

And what should people look out for? So whooping cough is an infection that used to be very common.

It's caused by a bacteria called pertussis. And the old kind of classic name for it is the

100-day cough. And it's famous for causing long-term respiratory illness. And in older kids and adults, the primary symptom is a very severe prolonged bouts of coughing.

And coughing that can be severe enough to cause a collapsed lung or a broken rib.

And so obviously, it's something that makes people pretty sick.

It turns out that the groups that are at the highest risk with whooping cough are people who

have compromised immune systems, so folks who have cancer or who are transplant recipients,

but especially young babies.

And one of the challenges with little babies is that instead of having coughing spells, they often will just stop breathing,

which is a reason

that those kids will often come into the hospital or even need ICU care with a breathing

tube to help them breathe. And so that's why we vaccinate starting at two months of age

to try and protect that population that's so vulnerable to severe disease with whooping cough.

And so why is it that whooping cough might cause worse symptoms in an infant than it would

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