Cough is a bacterial infection that can be particularly dangerous to babies and young children and is on the rise. In 2025, the United States has recorded 8,485 cases. Compared with the same period in 2024, this is compared with 4,266 cases.

Just like measles, it spreads at unprecedented levels, whooping cough (more formally known as whooping cough) can prevent whooping cough with a safe and effective vaccine. But with increasing anti-vaccination sentiment and cutting immunization services, children’s pertussis vaccination rates have declined in the past two years.

The conversation asked epidemiologist Annette Regan to explain why whooping cough has become so common and how families can protect themselves from the disease.

What is whooping cough and why is it dangerous?

Whooping cough is a preventable vaccine disease caused by bacteria Bordetella whooping cough. French researchers first confirmed B. Whooping cough Bacteria from 1906. It is believed that the first epidemic of whooping cough occurred in Paris in 1578.

Infection can lead to acute respiratory illness, characterized by severe and spastic cough mantras. The classic symptom of whooping cough is the “hoop” sound caused by someone trying to breathe during a cough. Severe complications of whooping cough include slowing down or stopping breathing, pneumonia, and seizures. Although older children and adults can also experience severe cases and deaths, the disease is the most severe.

Some doctors call whooping cough "a 100-day cough" because the symptoms can last for weeks or even months.

The World Health Organization estimates that 24.1 million pertussis cases and 160,700 deaths occur worldwide in children under the age of 5 years. Whooping cough is highly contagious. After exposure, 80% of people who have not been exposed to the bacteria or vaccinated with the disease develop an infection.

Fortunately, the disease can be largely prevented with a safe and effective vaccine, which was first licensed in the United States in 1914.

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How did the cases last year and this year compare to the past few years?

During the 19020 pandemic between 2020 and 2022, the number of whooping cough was lower than usual. This may be the result of limited social contact caused by social distancing, masking, school closures and lockdown measures, reducing the spread of the disease overall.

However, in the past two years, the number of whooping cough cases has exceeded the number before the pandemic. In 2024, local and state public health agencies reported 35,435 cases of pertussis to the Centers for Disease Control and Prevention — five times the 7,063 cases reported in 2023, while the 18,617 cases reported in 2019 nearly doubled the pace of the 2019 18,617 cases reported before the pandemic.

Between October 2024 and April 2025, at least four people died of whooping cough in the United States: two babies, one school-age child and one adult.

Why are those whooping cough cases rising?

Although the vaccine's pertussis infection in the United States has caused a sharp decline in vaccines, the incidence of the disease has been rising since the 1990s, except for a brief decline during the COVID-19-19 pandemic.

Before the routine childhood vaccination for whooping cough began in 1947, the cost hovered between 100,000 and 200,000 boxes per year. Using the vaccine, by the late 1950s, the annual rate dropped below 50,000, and in the late 1960s, less than 10,000 per year. They reached a low of 1,010 in 1976.

However, since the 1980s and 1990s, the United States and several other countries have been seeing a steady revival of pertussis cases, with more than 10,000 cases a year from 2003 to 2019. During the pandemic, they fell again to last year’s recovery.

There is no explanation as to why the cases have increased recently, but there are several factors that may cause them. First, whooping cough naturally occurs in an annular epidemic, peaking every two to five years. Between 2020 and 2022, the United States may enter one of these peaks. However, some scientists point out that the increase in cases is greater than what is usually expected during the usual peak period.

Some scientists point out that this obvious resuscitation is associated with changes in the type of vaccine used by children. Until the 1990s, the pertussis vaccine contained a whole vaccine B. Whooping cough Bacterial cells. Whole-cell vaccines can stimulate a lasting immune response, but are also more likely to cause fever and other vaccine responses.

In the 1990s, the national vaccine program began to transition to a vaccine containing purified components of bacterial cells but without the entire cell. Now, some scientists believe that while this partially cellular vaccine is unlikely to cause fever in children, it provides protection for a shorter time. Immunity after whole-cell vaccination is thought to last 10-12 years, while partial-cell vaccination is three to five years after. This means people may get infected more quickly after vaccination.

Vaccination rates have been less high since 2020 and have begun to fall into children. In the United States, the percentage of the latest kindergartens has dropped from 95% in the 2019-20 school year to 92% in the 20233-24 school year. Even fewer teenagers receive boost doses.

How do people protect themselves and their families?

Routine vaccination for children starting in infancy and then intensifying doses in adolescents and adults can help maintain high immunity.

Public health experts recommend children receive five doses of pertussis vaccine. According to these recommendations, they should receive the first three doses at 2, 4 and 6 months of age and then add two more doses at 15 months and 4 years of age, with the aim of providing protection through early adolescence.

Babies under 6 weeks are not old enough to receive the whooping cough vaccine, but the risk of severe illness in whooping cough is the greatest. Vaccination during pregnancy may provide protection due to antibodies delivered from the mother to the developing fetus. Now, many countries, including the United States, are advised to receive a whooping cough vaccine between 27 and 36 weeks of each pregnancy to protect the baby.

To maintain protection against whooping cough during childhood, it is recommended to use an enhanced dose of pertussis vaccine for adolescents aged 11 to 12 years old. The CDC recommends that all adults receive at least one booster dose.

As immunity decreases over time, people who come into contact with babies and other high-risk groups such as caregivers, parents, and grandparents may benefit from additional booster doses. If feasible, the CDC also recommends boosting doses for adults aged 65 and older.

Over the past 80 years, vaccine safety studies have proven that the pertussis vaccine is safe. About 20 to 40% of vaccinated babies experience local reactions such as pain, redness and swelling at the vaccination site, while 3 to 5% of vaccinated babies suffer from low-grade fever. The more severe reactions are much less, with less than 1% of vaccinated babies.

The vaccine is also very effective: 98% of children are protected by whooping cough in the first year after receiving all five doses of the pertussis vaccine. Five years after the fifth dose, 65% of vaccinated children remain protected.

Promoting vaccination during adolescence protects 74% of adolescents from whooping cough, and promoting vaccines during pregnancy protect 91% to 94% of immune babies from hospitalization caused by whooping cough.

Families can discuss with regular health care providers whether their children, themselves or other family members need a whooping cough vaccine.