US Sees Sharp Rise in Whooping Cough Cases Amid Falling Vaccination Rates

Health officials across the United States are closely monitoring a concerning resurgence of whooping cough, also known as pertussis, as cases continue to climb in 2025.

Preliminary data from the Centers for Disease Control and Prevention (CDC) report at least 8,485 cases so far this year—more than double the number recorded during the same period in 2024.

The increase follows a pattern noted by experts: pertussis cases tend to peak every two to five years. However, public health officials warn that the recent spike may also reflect a deeper trend—declining vaccination rates and growing vaccine hesitancy. Childhood immunization rates have fallen below the 95% threshold necessary to maintain herd immunity, and the number of vaccine exemptions among kindergarteners is at an all-time high.

“There’s unfortunately been increasing anti-vaccine sentiment in the United States,” said Dr. Ericka Hayes of the Children’s Hospital of Philadelphia. “Our recovery [in vaccination rates] is not nearly as quick as we expected or needed it to be.”

Whooping cough is a highly contagious respiratory illness caused by the bacterium Bordetella pertussis. It typically begins with cold-like symptoms but can progress into severe coughing fits that may last for weeks. The disease poses the highest risk to infants, especially those too young to be vaccinated, and can be fatal in severe cases.

In recent months, several deaths have been linked to the illness, including two infants in Louisiana, a young child in Washington state, and an adult in Idaho. In 2024, the US recorded around 35,000 pertussis cases and approximately 10 related deaths. If current trends continue, experts estimate that the nation could see as many as 70,000 cases in 2025—potentially the highest number in over 70 years.

The pertussis vaccine, typically given in combination with diphtheria and tetanus (as DTaP or Tdap), is considered effective at preventing serious illness. The CDC recommends a series of doses for infants starting at two months of age, as well as booster shots for older children, adults, and pregnant women to protect newborns.

However, vaccine uptake is uneven across the country. Some regions, such as Pennsylvania and Michigan, have reported hundreds of cases already this year, particularly in urban centers and among school-aged children. In some school districts, vaccination rates have dropped as low as 30%, creating vulnerable populations where outbreaks can more easily spread.

Public health officials attribute the decline in vaccine coverage to several factors, including misinformation, pandemic-related disruptions, and waning public memory of how dangerous these diseases can be.

“Pertussis isn’t just a routine childhood illness,” said Chad Neilsen, head of infection control at Nemours Children’s Health in Florida. “It can be very serious, especially for young children and babies.”

Neilsen and other experts stress the importance of clear communication about the safety and benefits of vaccines. Efforts to improve vaccination rates include encouraging expectant mothers to get vaccinated during pregnancy and addressing concerns among vaccine-hesitant parents.

Though most cases of whooping cough can be treated with antibiotics, early diagnosis is crucial to reducing the severity of symptoms and limiting the spread. As health systems prepare for a potentially challenging year, officials are urging the public to stay informed, up to date on vaccinations, and mindful of symptoms—especially during seasonal peaks in spring and fall.

With input from the Associated Press and ABC News.