History
Pertussis, commonly known as whooping cough, was once a leading cause of illness and death among children in the United States. Before the introduction of a vaccine in the 1940s, the disease affected more than 200,000 people each year. Thanks to widespread immunization efforts, reported cases dropped by over 90%.
However, in recent years, pertussis cases have begun to rise again. This resurgence is causing concern among health experts, particularly due to the risk of severe complications in infants, the elderly and those with weakened immune systems.
In this blog, we’ll explore what’s behind the increase in pertussis cases in the U.S. and the steps we can take to address this growing health concern.
What is pertussis?
Whooping cough is a highly contagious respiratory infection caused by the Bordetella pertussis bacteria. It’s known for the “whoop” sound a person makes after a severe coughing fit. The illness can be especially dangerous for babies, leading to serious problems like pneumonia, seizures and even death. Vaccines have dramatically reduced the number of cases, but recent data shows it’s not as controlled as once thought.
The rise in pertussis cases in the U.S.
Whooping cough is on the rise again. According to the CDC, more than 15,000 cases were reported in 2022 –– up from 10,000 in 2021. This increase has been observed across multiple states, affecting both urban and rural communities. Health experts are concerned that the U.S. may be losing progress in controlling this disease.
Several factors may be driving this increase:
Decreasing immunity
While the pertussis vaccine is effective and helps reduce the number of cases, its protection fades over time. Studies show that immunity starts to decline 5 to 10 years after vaccination. This means teens and adults more likely to get sick and spread the disease, especially to babies and those at higher risk.
To prevent this, the CDC recommends:
- A Tdap booster at age 11 or 12
- A Tdap vaccine during each pregnancy –– the antibodies are passed to newborns
- A Tdap vaccine for any adult who has never received it, especially if they are around infants
Vaccine hesitancy
Even though the vaccine is safe and effective, some people choose to delay or skip vaccines because of fear or misinformation. This means the disease can spread more easily.
When most people in the community are vaccinated, we have herd immunity. This protects those who can’t get the vaccine including newborns, patients being treated for cancer and other vulnerable groups.
Missed or unreported cases
Some cases of whooping cough may go unnoticed or unreported, especially when symptoms are mild or resemble the common cold. Not everyone gets the classic “whooping” sound, which can lead to misdiagnosis and unintentional spread of the disease.
Improved recognition of symptoms and better disease tracking are key to identifying cases early and preventing outbreaks.
Impact on vulnerable populations
The return of whooping cough is particularly dangerous for vulnerable groups –– especially infants too young to be vaccinated. Pertussis remains a leading cause of vaccine-preventable deaths among babies in the U.S., with those under 6 months at the highest risk.
To protect them, the CDC recommends:
- Pregnant individuals receive a Tdap vaccine during each pregnancy
- Adults who are frequently around infants should also get vaccinated, including parents, caregivers and health care providers
Why vaccines matter
Despite challenges like fading immunity and misinformation, vaccines are still the most effective tool for preventing whooping cough.
The CDC recommends:
- A series of DTaP shots for children
- A Tdap booster for teens and adults
- Vaccination during pregnancy to protect both mother and baby
Getting vaccinated helps prevent the spread and protects everyone –– especially those most at risk.
What you can do
The rise in whooping cough cases shows gaps in vaccine coverage and immunity.
Here’s how you can help:
- Ensure you and your family are up to date on vaccines
- Speak with your health care provider about your vaccine history
While the increase is concerning, it can be managed. With continued public awareness and addressing issues like fading immunity, vaccine hesitancy and early diagnosis, we can slow the spread and protect our communities.
Sources
- Centers for Disease Control and Prevention. (2024). About Whooping Cough. Centers for Disease Control and Prevention. https://www.cdc.gov/pertussis/about/index.html
- Wood, M. (2023). Waning immunity and the resurgence of pertussis. Journal of Infectious Diseases, 232(5), 875–882.
- McNeil, M., & Armstrong, C. (2022). The role of vaccine hesitancy in pertussis outbreaks in the U.S. Vaccine, 41(13), 1561–1570.
- American Academy of Pediatrics. (n.d.). How to protect your children during a measles outbreak. HealthyChildren.org. https://www.healthychildren.org/English/safety-prevention/immunizations/Pages/how-to-protect-your-children-during-a-measles-outbreak.aspx
