A syringe containing a Tdap vaccine protecting against tetanus, diphtheria and pertussis is pictured at the Parkview Physicians Group – Family Medicine office in Peru. Cases of pertussis, also known as whooping cough, have risen sharply across the U.S. in 2024 compared to the past four years and doctors are reminding that immunization is the best defense against this bacterial lung infection. Image provided by Parkview Health.

News Release

FORT WAYNE — A national increase in pertussis cases is causing concern for physicians, who urge prevention as the best way to battle the bacterial lung infection that’s on the rise in 2024, according to a news release from Parkview Health.

Pertussis, also known as “whooping cough” for the loud sucking, whooping sound it causes as those infected struggle to breathe in, is a vaccine-preventable disease that’s been making a comeback since a drop during the pandemic.
So far this year, for the week ended Dec. 7, the Centers for Disease Control and Prevention has recorded 30,258 cases of pertussis reported by states and U.S. territories, nearly quintupling the total number of cases seen at the same point in 2023 at 6,161.

Indiana has reported 411 cases year-to-date, also significantly up from 153 in 2023, according to the CDC’s infectious disease reporting database.

Pertussis is a bacterial infection spread through respiratory droplets. When contracted, the bacteria settle in the lungs and release toxins that paralyze cilia — small hairlike structures that help clear debris, germs and fluid — allowing for a buildup of mucus that causes violent, painful coughing.
“You cough severely and can break ribs,” said Dr. Stephen Clingman, Parkview Physicians Group – Family Medicine, Peru. “When you breathe in you can make this ‘whoop’ sound. That cough can last for many, many days. It can lead to pneumonia and hospitalization.”

Like many respiratory diseases including flu and RSV, small children are among the most vulnerable and most in danger if they contract whooping cough because their immune systems and bodies are less developed compared to older children or adults.

Pertussis is one of those diseases that physicians rarely or ever see, Clingman said, primarily because there’s been an effective vaccine for it for years. In his 30 years of practice, Clingman said he’s seen around five cases.

But with falling immunization rates — Indiana’s on-time vaccination rate for 3-year-olds was over 70% in 2020 and rising but has fallen to just 58.6% overall in 2024 — these types of preventable diseases are beginning to pop up more often.

Pertussis vaccines are one of the standard childhood immunizations and come in five doses, delivered at 2, 4, 6 and 15 months and then a final dose at 4 years old, with a booster recommended at age 11.

Before the 1990s, the pertussis vaccine was given as a live vaccinem which created a strong immunity but could cause infections or other side effects. Since then, the vaccine was redeveloped as an inactive formulation, which rarely causes side effects but has the downside of the immunity weakening over time, according to Clingman. It’s now recommended that adults get at least one booster in their lifetime, and it’s usually administered as part of a combination Tdap vaccine when adults get a 10-year tetanus booster.

Because of the different vaccine types, some people who have been immunized against pertussis may still rarely contract it. Even if they do, their odds of developing a severe case are greatly lessened, Clingman said.

The rise in pertussis cases today likely has multiple causes, Clingman explained, including lower immunization rates, fading vaccine immunity, cessation of pandemic-era precautions like masking and social distancing, and better identification and reporting of cases.

Like most illnesses with available vaccines, pertussis is highly contagious but also highly preventable.

Prior to the development of the first pertussis vaccine in the 1940s, the U.S. used to average 150,000-200,000 cases of whooping cough per year. The disease was well controlled within decades once vaccines rolled out, with fewer than 2,500 cases per year from 1973-1984.

Whooping cough incidence has risen since the advent of the inactive vaccine formula — 10,000 to 25,000 cases annually was the average from 2003-2019, with spikes as high as 48,000 in 2012 — but significantly fell during the COVID-19 pandemic as people took action to prevent the spread of respiratory diseases to an average of fewer than 4,000 cases over the last three years.

Whether whooping cough is simply returning to its pre-pandemic numbers or starting to rise in prevalence, immunization remains the easiest, safest and most effective way to protect yourself from pertussis, Clingman said. Anyone with questions or concerns should talk to their pediatrician or family doctor.

“I always like to emphasize the importance of vaccines. Even if they don’t last forever, they are very, very effective,” Clingman said. “These diseases are things that can put you in the hospital and kill you. It’s like wearing a seat belt. It’s important, you might never need it, but that one time you do you’ll be glad you had it.”

Pertussis By The Numbers

U.S. Cases

• 2020: 6,124
• 2021: 2,116
• 2022: 3,044
• 2023: 6,161*
• 2024: 30,258*

Indiana Cases

• 2023: 153*
• 2024: 411*

*As of Dec. 7. Source: Centers for Disease Control and Prevention