It’s highly infectious and definitely not a welcome Thanksgiving guest.
Pertussis, also known as whooping cough, is on the rise with outbreaks across the country, leaving some parents of infants wondering whether they should travel or visit family at all.
Pertussis is a bacterial respiratory infection characterized by the “whoop” sound made by sharp intakes of breath between coughing fits. Infected adults and kids can develop a brutal, weekslong cough. Sick infants are at risk of dying.
Vaccination offers strong protection against disease, but immunity wanes over time and Centers for Disease Control and Prevention data show fewer children are getting the vaccine. The CDC recommends adults get a Tdap booster shot every 10 years.
Infections dropped nationally during and after the COVID-19 pandemic. In 2024, cases surged. This year, infections are similarly high. As of Nov. 19, preliminary data showed more than 25,000 cases nationwide in 2025. The states of Washington, California, Florida and Oregon have been hardest hit.
Heading into the holidays, what are the symptoms to watch for, who is most at risk and who needs to get vaccinated?
Symptoms to be on the lookout for
Whooping cough symptoms progress in stages, and the disease’s severity can depend on a person’s vaccination status.
Symptoms usually appear within five to 10 days after exposure, but they can also take twice as long to develop.
During the first one to two weeks, symptoms often resemble an average cold: a mild cough, a low-grade fever and a runny nose. Although the symptoms might seem innocuous, a person is contagious during this stage.
The second, more severe stage can last up to 10 weeks. The main symptom is intense coughing fits, called paroxysms, that can lead to vomiting. The cough ends with an intake of breath that sounds like a “whoop.”
“Sometimes the coughing is so severe that ribs are cracked,” said Dr. Joseph Bocchini, a pediatric infectious disease doctor at Willis-Knighton Health. “There’s such shortness of breath that people wake up at night with a coughing spell, they feel like they’re suffocating.”
Pneumonia is another possible complication.
People who have never been vaccinated are likely to experience worse symptoms than their vaccinated peers, Bocchini said.
Recovery is often gradual as the cough wanes. As a person recovers, they can be more vulnerable to contracting other respiratory infections, and the cough might return.
Getting sick confers natural immunity from the disease for a time, but that protection doesn’t last long.
Infections happen year-round, but peak whooping cough season lasts from late summer through fall. Pertussis is a cyclical disease, meaning it might spread widely through a community and then disappear from that population. Infections might return to an area once that immunity has waned.
What causes the cough?
The bacteria Bordetella pertussis causes the coughing.
The bacteria enter a person’s upper respiratory tract and latch on to cilia, hair-like extensions in the airways. Cilia are essential for clearing mucus and debris from your lungs. The bacteria release a toxin that damages the cilia and causes the airway to swell. With a person’s lung-cleaning apparatus damaged, the body resorts to coughing to get the gunk out.
If one person in a household is infected, data shows about 80% of exposed family members also will get infected, if they aren’t vaccinated or immune.
Pertussis spreads through droplets when someone sneezes or coughs.
How is whooping cough treated?
Doctors use nasal swab lab tests to identify infections.
Antibiotics are the most effective treatment, especially when taken early in the illness. If taken before the coughing fits begin, antibiotics can prevent the illness from progressing or make symptoms milder.
That’s why doctors sometimes prescribe antibiotics to the infected person’s family and other contacts: to halt further spread.
Once the coughing fits have begun, antibiotics are less effective at reducing symptoms or shortening the course of the illness. The cilia have already been damaged, and the lungs need time to heal.
Antibiotics are still prescribed at that stage because a five-day course kills the bacteria, making the person no longer contagious, even if the cough persists.
To manage symptoms, the CDC advises using a cool-mist humidifier, eating small meals to prevent vomiting and drinking plenty of fluids. The agency also recommends avoiding airway irritants such as dust, smoke or chemical fumes that might trigger coughing.
Some pertussis cases require hospitalization.
Young babies are most at risk
Whooping cough is most dangerous for babies under 1 year old, especially under 3 months. The CDC reports that 1 in 3 infected babies will need hospital treatment. About 1% of infected babies die from complications, such as pneumonia, damage in the brain or difficulty breathing.
Infants with pertussis sometimes don’t cough at all, but have dangerous pauses in breathing called apnea. Babies may turn blue as they struggle to breathe.
Older people, people who are immunocompromised and people with moderate to severe asthma also could be at higher risk of complications.
DTaP and Tdap vaccines can protect against illness
Scientists first developed a pertussis vaccine in 1914. In the 1940s, it became part of a combination vaccine that also protects against diphtheria and tetanus. It’s still combined with those today.
Two vaccines protect against whooping cough: DTaP, given to young children, and Tdap, given to adolescents, adults and pregnant women.
Vaccination doesn’t stop the bacteria from entering a person’s body, but it helps stop an infection from developing. Among the minority of vaccinated people who do get sick, vaccination decreases the illness’ severity.
The CDC’s childhood vaccine schedule recommends that babies get their first dose of the DTaP vaccine at 2 months old. The vaccine is delivered in four more doses at 4 months, 6 months, between 15 and 18 months and between 4 and 6 years.
“Just like we practice baseball or piano with many games of catch or lessons, providing multiple doses gives our immune system additional practice,” said Dr. Lori Handy, a pediatric infectious disease specialist at Children’s Hospital of Philadelphia. “The vaccine schedule is designed to give enough practice to our system that eventually, the person is adequately protected.”
Vaccinated children are much less likely than unvaccinated children to get sick with pertussis.
During the 2024-2025 school year, 92.1% of kindergarteners received a DTaP vaccine, down from about 95% in the decade before the pandemic.
Protection from the vaccine wanes over time, which is why we have the Tdap booster vaccine. The CDC recommended preteens get one dose, and adults get a shot every 10 years. Adults can infect children, so staying up to date is important for the little ones in your life.
The CDC also recommends pregnant women receive a Tdap booster between the 27th and 36th week of pregnancy, regardless of when they were last vaccinated. “Vaccination of pregnant moms provides immunity to newborn babies, so that they are protected at the time when they are most at risk of deadly disease,” Handy said.
How can I stay safe over the holidays?
“Far and away, the most important thing is to be vaccinated and be up to date,” Bocchini said. And if you have a small baby, make sure the people around the baby are also vaccinated and up to date.
Other strategies are basic: Wash your hands often. Use good cough etiquette. Teach these habits to your kids.
Since the bacteria spreads through coughs and sneezes, wearing a mask can help slow the spread, whether you are infected or around someone who is.
If you think you might have been exposed, you can ask your doctor to test you. In its initial stage, whooping cough is hard to distinguish from other respiratory infections, Bocchini advised patients to ask themselves how they might have been exposed: Have I been around someone with a persistent cough that happens in fits? Although it may be hard, it’s safest to stay home when you are sick.
