Surging Whooping Cough Cases Highlight the Importance of Vaccination

This is a highly detailed and realistic close-up of Bordetella pertussis, which causes whooping cough (pertussis), a highly contagious respiratory disease. (AI)

(Adobe Stock 958655470 by phurinee)

Experts like Michael Glazier, MD, warn that waning immunity, declining vaccination rates, and increased transmission are driving this resurgence. Vaccination remains the best defense, with pediatricians urging timely immunization to protect vulnerable populations and prevent further outbreaks.

With the recent measles outbreak in Texas and Kansas, parents and health care providers are also concerned about other infectious diseases that vaccines can prevent.

One disease is pertussis or whooping cough. Whooping cough is a highly contagious respiratory infection that can cause severe coughing fits, breathing difficulties, and dangerous complications, particularly in infants. Early symptoms resemble the common cold, but violent coughing spells begin within weeks, sometimes lasting for months. These fits can make breathing, eating, or sleeping difficult, and in some cases, infants may turn blue due to lack of oxygen.

The illness progresses through 3 stages: mild cold-like symptoms, severe coughing fits, and gradual recovery. The Bordetella pertussis bacteria damage airway linings, leading to thick mucus buildup that triggers relentless coughing. It spreads easily through respiratory droplets and remains contagious for weeks.

Complications can be severe, especially for babies under 12 months, leading to pneumonia, malnutrition, seizures, or even death. Adults and adolescents can suffer from broken ribs, fainting, or weight loss due to prolonged coughing.

Diagnosis involves a physical exam and lab tests, and treatment typically includes antibiotics to reduce transmission. However, the best defense is vaccination. DTaP and Tdap vaccines help prevent infection and lessen severity if contracted. Prompt medical attention, rest, hydration, and symptom management can aid recovery. Without intervention, whooping cough remains a significant public health threat.

To learn more about whooping cough, Infection Control Today^® (ICT^®) spoke with pediatrician,

Michael Glazier, MD, cofounder and chief medical officer of Bluebird Kids Health, spearheads initiatives to transform pediatric care for children and their families. With more than 25 years of experience in pediatrics, he is committed to delivering exceptional and personalized healthcare. After earning his medical degree from Tufts University in 1999, he has focused on making high-quality health care accessible to all children. Glazier is a passionate advocate for preventive care, highlighting the significance of regular checkups to promote the health and well-being of young patients.

ICT: Since whooping cough cases have tripled this year, what factors contribute to this surge, and why are children particularly at risk?

MG: [The cases] may have, even at this point, increased roughly 5 times in the 2024-2025 season compared to the 2023 season. It’s interesting times with [CDC] webpages going up and down. But there are about 30 to 35,000 cases, significantly more than the 7,000 in 2023. However, it's not unusual when compared to prepandemic years. Part of this increase reflects a slight return to prepandemic levels, while another part is due to waning immunity, particularly among adults. I also worry about declining vaccination rates in children moving forward.

ICT: Considering waning immunity, what about people who are in their mid-50s, especially those with comorbidities like asthma?

MG: [With] plane travel [and] getting sick, and [doctors] bringing things home from the clinic [from children] reflects what we see, except that often pertussis spreads the other way, from adults to kids. I'm less concerned about an adult than I am about an infant, even considering asthma.

For pertussis, though, the biggest risk factor is that the patients who have the most struggle with it are the newborns and the infants when they're too young to get vaccinated. Pertussis is caused by a bacteria, Bordetella pertussis, that releases a toxin with an infection, and that toxin does 2 things: it increases our mucus production, and we develop this thick, tenacious mucus that is hard to clear, and at the same time, that toxin decreases. A little complicated, but what's called our mucociliary escalator, which helps us clear things from our bronchioles, which are our air tubes, and that combination of like thick mucus and a difficulty clearing it is what leads to trouble.

For you and me [as adults], we have relatively big airways compared to a newborn or infant who has small ones, and so just based on that small infant diameter, their underdeveloped immune system and the additional complication that sometimes, instead of just coughing, they can get periods of apnea where they stop breathing that places them at the greatest risk.

If a newborn or an infant who is under-vaccinated—not by choice but simply by age—can experience decreased oxygenation due to apnea or that horrible difficulty in clearing mucus, this can lead to seizures, oxygen deprivation, and potentially death. This is the highest risk group.

The earliest we can give a vaccine for an infant is at 6 weeks, although we typically start at 8 weeks, as that aligns with the well-child visits when vaccinations begin, according to the American Academy of Pediatrics. We provide the whooping cough or pertussis vaccine at 2 months, 4 months, 6 months, again at 15 to 18 months, and then again at ages 4 to 5 [years]. These initial vaccines prime the immune system, and the subsequent boosters enhance the antibody response and prolong its effectiveness. Receiving the last booster at ages 4 to 5 is helpful, but we do give another booster at ages 11 to 12. As we learn more about this, we're finding it's unpredictable how long immunity lasts. Returning to the question, part of the resurgence may be that what we believed was a longer period of immunity is shorter.