The US has seen nearly 28,000 whooping cough cases this year. Here’s what you need to know

For the second year in a row, the US has surpassed 25,000 whooping cough cases — a troubling sign linked to declining vaccination levels.

Often called the “100-day cough,” whooping cough, or pertussis, begins with cold-like symptoms such as runny nose, fever, or cough. These symptoms can progress to severe coughing fits that may last weeks or even months, according to the US Centers for Disease Control and Prevention (CDC). A characteristic “whoop” sound when coughing often appears in the second phase of the illness.

Whooping cough can lead to serious complications, including severe illness or death, especially among young children. About one in three babies younger than 1 year old who contract whooping cough require hospital care. However, experts believe many cases go unrecognized and unreported, the CDC notes.

### Pertussis Cases on the Rise

The CDC reported nearly 28,000 whooping cough cases in the US this year, marking an elevated level following last year’s peak of 35,493 cases. In contrast, only 7,063 cases were reported in 2023. The last time pertussis cases were this high was in 2014 when 32,971 cases were documented.

Thirteen deaths from pertussis have been reported in the US in 2025, according to the Pan American Health Organization (PAHO), with most fatalities occurring in children under 1 year old.

The rise in whooping cough is not unique to the US. The PAHO, which serves as the World Health Organization’s office for the Americas, reported 977,000 pertussis cases last year — a five-fold increase over 2023.

### Causes Behind the Increase

Dr. Scott Roberts, associate medical director for infection prevention at Yale School of Medicine, believes that falling vaccination rates combined with a loss of population-wide immunity during the COVID-19 pandemic contribute to the surge.

“I worry vaccine hesitancy is playing a role. This is a vaccine-preventable illness, and any decline in vaccine rates will lead to increases in pertussis,” he stated.

### Vaccines Prevent Whooping Cough

The CDC recommends routine diphtheria, tetanus, and pertussis (DTaP) vaccination for all infants and children under 7 years old. The vaccine is given as a five-dose series starting at 2 months of age. Children who receive all five doses on schedule are 98% protected from illness within the year following the last dose, and about 70% remain protected five years later.

For adolescents and adults, booster vaccinations with Td or Tdap are recommended every 10 years, starting between ages 11 and 12. Dr. Roberts emphasizes choosing the Tdap booster, which protects against pertussis.

“Last year, we had a lot of college outbreaks. Many people get their childhood vaccine series but then skip the booster series,” he explained. These outbreaks were often fueled by students living in group settings where the disease spreads easily.

The return to shared indoor spaces after COVID-19 restrictions may also have contributed to the increase. “Limited exposure to routine pathogens during the pandemic meant that now a greater proportion of people are being exposed to pertussis all at once,” Roberts said. “We may still be recovering from a loss of population immunity, but things could stabilize over the next few years.”

### Declining Vaccination Coverage

PAHO highlights that Tdap vaccination coverage in the Americas dropped to its lowest level in two decades during the COVID-19 pandemic, with rates for the first and third doses falling to 87% and 81%, respectively, in 2021.

### Importance of Vaccination for Pregnant Women

Roberts also stresses the importance of pertussis vaccination for pregnant women. The CDC recommends a Tdap booster between weeks 27 and 36 of pregnancy, regardless of previous vaccination status.

“When a pregnant woman gets the vaccine, she develops antibodies that cross the placenta and provide the newborn with some immunity,” Roberts said. However, these maternal antibodies weaken after a few months, which is why it’s critical for babies to complete the DTaP vaccine series on schedule.

### Whooping Cough Symptoms and Treatment

Whooping cough differs from flu, COVID-19, and the common cold in that it is caused by the bacterium *Bordetella pertussis*, not a virus, says Dr. Shira Doron, chief infection control officer for Tufts Medicine.

“Even though early symptoms resemble viral respiratory infections, the bacterial nature of whooping cough leads to very characteristic signs,” Doron explained. After one or two weeks, some patients develop the classic whooping sound when gasping for breath between coughing fits. Severe coughing can also trigger post-tussive emesis, which is vomiting during or following coughing episodes.

People experiencing severe worsening cough, vomiting, or the distinctive whooping sound should seek medical attention promptly, as these symptoms indicate airway damage caused by bacterial toxins.

Antibiotic treatment is the mainstay for whooping cough. When started early, antibiotics can reduce contagiousness and help break the chain of transmission, though they do not alter the illness’s course.

Because rapid pertussis tests are often unavailable, many healthcare providers prescribe antibiotics based on symptoms alone. Azithromycin, a commonly used five-day antibiotic course (“Z-Pak”), effectively kills the bacteria.

### Whooping Cough Risks and Emergency Signs

Infants and young children are at higher risk for severe illness due to their developing respiratory and immune systems. Those showing signs of respiratory distress — such as struggling to breathe or skin turning blue — require immediate emergency care.

Severe cases of pertussis are rare among vaccinated children, Roberts noted.

### Local Health Officials Urge Vaccination

Health officials nationwide have noticed declining vaccination rates and subsequent increases in pertussis cases.

In South Carolina, health authorities recently urged residents to stay current on vaccinations amid a concerning rise in measles, whooping cough, and chickenpox.

Dr. Linda Bell, South Carolina’s state epidemiologist, linked the increase to declining vaccine coverage. “This trend is both preventable and reversible,” she said. “Vaccines are one of the most effective tools we have for protecting our communities. Choosing not to vaccinate can put not just yourself but your neighbors, loved ones, and others at risk.”

Similar patterns have emerged in North Carolina. Dr. Raynard Washington, director of Mecklenburg County Public Health, reported a spike from one or two annual whooping cough cases to 68 in 2024 and 48 cases by October 2025. Many cases occurred in children not up to date with the five-dose vaccine series, often clustered in communities where families delay or refuse vaccines.

“These clusters increase risk in those neighborhoods,” Washington said. Older adults are also vulnerable due to weakened immune systems, and he recommends that grandparents and others speak to their healthcare providers about protection options.

Dallas County, Texas, has seen a dramatic increase as well, with 40 cases in 2023, 160 in 2024, and at least 195 so far in 2025. According to state data, kindergarten vaccination rates against pertussis dropped from nearly 94% in the 2023-24 school year to under 90% in 2024-25.

Dr. Phil Huang, director of Dallas County Health and Human Services, urges parents to ensure their children are fully vaccinated. “That’s the best protection that we can provide,” he said.

### Monitoring and Early Care

Roberts advises families to monitor local public health websites for vaccine-preventable disease outbreaks, which may influence diagnosis and treatment approaches.

“If parents are concerned or symptoms persist for more than a couple of weeks, it’s important to see a doctor,” he said.

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Staying up-to-date on whooping cough vaccinations and recognizing symptoms early can protect individuals and communities from this potentially serious illness.
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