Fort Worth infants at greater risk for whooping cough illness as vaccine rates dip

Fewer Tarrant County kids are protected against whooping cough, a disease that can range from annoying to miserable for adults but that can be deadly for infants, according to a Star-Telegram analysis of vaccination data.

The rate of county kindergartners up-to-date on their DTaP vaccines, which protect against diphtheria and tetanus as well as whooping cough, has dropped from 95% to 92% between 2019 and 2023, according to state data.

In Fort Worth’s school district, the county’s largest, kindergartners vaccinated dropped from 94% in the 2019-20 school year to 83% in the 2023-24 year. Most of those unvaccinated students are considered “delinquent” by the state health department, meaning they haven’t filed a conscientious objection to getting vaccinated and are behind on their scheduled immunizations.

Whooping cough, also known as pertussis, is caused by a bacteria. Immunity from whooping cough tends to fade about seven years after you’ve been vaccinated or infected by the bacteria. Because of the fading immunity, outbreaks are common in the U.S.

“Of the vaccine preventable illnesses we have, pertussis is the one that causes the most outbreaks that we see on a fairly regular basis,” said Dr. Robert Frenck, the director of the Vaccine Research Center at Cincinnati Children’s Hospital.

Unlike a virus like measles, pertussis is always present in the U.S. Exactly what causes whooping cough to erupt into an outbreak is unclear.

For most healthy adults, the whooping cough is an annoying illness. It’s known as the “100 day cough” because of how long its symptoms persist. Although it’s rarely fatal for adults, “it’s a very unpleasant infection,” said Dr. Mark Sawyer, a professor of pediatric infectious diseases at the University of California San Diego.

But vaccines are critical for protecting infants, who can get seriously ill from the disease. Because their airways are so small, babies with whooping cough can struggle to breathe. One out of every three infants who get whooping cough require hospitalization, according to the U.S. Centers for Disease Control and Prevention. About 1% of infants die from complications of the disease.

“The real small ones are the ones we’re worried about,” Frenck said.

Because whooping cough is so serious for babies under the age of 1, pediatricians encourage families to do what’s known as “cocooning” when a family is expecting a child, in which everyone who will be spending time with the baby gets an updated pertussis vaccine to protect the child, Frenck said. This method surrounds the child in a community of people that is unlikely to spread whooping cough to the infant.

The Star-Telegram analyzed vaccination rates for all six of the vaccines required for Kindergarten entry in Texas. Students can be exempt from receiving vaccines for medical reasons — such as an allergy to a vaccine or one of its ingredients — or for reasons of conscience. Although the DTaP vaccination rate has declined across the county, the decline has not be as steep as the rates for measles and chickenpox vaccines, which both declined by about five percentage points.

The reasons behind the decline in vaccinations are complex, and include multiple disruptions to routine pediatric care during and after the COVID-19 pandemic and changing attitudes among some parents toward vaccines and science more broadly, the Star-Telegram previously reported.

There were 32,000 cases of whooping cough last year, the most since 2014, according to CDC data. An outbreak forced the cancellation of a football game in September between Portland State and South Dakota.

Pertussis outbreaks are cyclical, and typically increase every three to five years, Sawyer said, so last year’s increase isn’t necessarily a reflection of lower vaccination rates. But, he added, if vaccination rates remain persistently low, the risk for every community, including Fort Worth, will increase. Pertussis comes in waves, and peaks of those waves will be “bigger and longer” if overall vaccination rates stay below 90%, he said.

The end result is that unprotected infants will likely die from a preventable disease. In 2010, California experienced a major pertussis outbreak. More than 800 infants were hospitalized, and ten died.

This story was originally published January 13, 2025 at 6:00 AM.

Ciara McCarthy

Fort Worth Star-Telegram

817-203-4391

Ciara McCarthy covers health and wellness as part of the Star-Telegram’s Crossroads Lab. She came to Fort Worth after three years in Victoria, Texas, where she worked at the Victoria Advocate. Ciara is focused on equipping people and communities with information they need to make decisions about their lives and well-being. Please reach out with your questions about public health or the health care system. Email cmccarthy@star-telegram.com or call or text 817-203-4391.