Alarming rise in whooping cough cases as vaccination rates drop, investigation finds

Whooping cough cases are on the rise as the vaccination rate for the highly contagious respiratory illness drops, a new investigation has found.

Pertussis, also known as whooping cough, is caused by a type of bacteria called Bordetella pertussis. It starts out like a common cold, but violent coughing fits later develop and linger for months, according to the Centers for Disease Control and Prevention.

Babies under one year old are at the greatest risk for getting whooping cough and can have life-threatening symptoms, the CDC says. Many babies with whooping cough don’t cough at all and instead have trouble breathing.

As of December 6, the CDC tracked 26,632 cases of whooping cough this year. It’s fewer than the 38,855 recorded during the same time last year, but significantly more than the 7,063 cases reported in 2023.

An NBC News/Stanford University investigation has found that roughly 70 percent of counties and jurisdictions in 31 states fell below the 95 percent target vaccination rate for whooping cough in children.

The CDC says the best way to prevent whooping cough is for people of all ages to get vaccinated. It is recommended that young kids get the DTaP vaccine, which protects against pertussis and the bacterial diseases diphtheria and tetanus.

In states that provided the investigation with data back to 2019, more than 75 percent of counties and jurisdictions had declining DTaP vaccination rates.

These numbers speak to a wider decline in childhood vaccination rates for a variety of illnesses across the country since vaccine skepticism began to increase during the Covid-19 pandemic.

During the 2024-2025 school year, coverage with the DtaP vaccine, the polio vaccine, the varicella vaccine, which protects against chickenpox, and the MMR vaccine, which protects against measles, mumps and rubella, decreased in more than half of states compared to the year before, the CDC says.

Whole-cell whooping cough vaccines were first licensed in the U.S. in 1914 and were available as a combined vaccine with diphtheria and tetanus inactivated toxins in 1948.

Up until the 1950s, whooping cough would affect anywhere from about 70,000 to 265,000 people each year, according to CDC data that goes as far back as 1922.