Whooping cough can be deadly, especially for babies under one year old. Globally, an estimated 160,700 children under five died from the disease in a single year (2014), and infants too young to be vaccinated face the highest risk. For older children, teens, and healthy adults, whooping cough is rarely fatal, though it can still cause weeks of miserable coughing and serious complications.
Infants Face the Greatest Danger
Babies under 12 months old account for the vast majority of whooping cough deaths. Their airways are tiny, their immune systems are immature, and they often can’t generate the forceful cough needed to clear mucus. In 2025, three unvaccinated infants in Kentucky died from the disease, none of whom had mothers who were vaccinated either.
The numbers for hospitalized infants are sobering. Among those sick enough to reach an intensive care unit, roughly 55% need a breathing machine. About 68% of infants with whooping cough experience apnea, episodes where they simply stop breathing. Pneumonia develops in about 22% of infant cases. These complications can spiral quickly: oxygen deprivation can trigger seizures, brain damage, or a dangerous spike in blood pressure inside the lungs that the heart can’t overcome.
How Whooping Cough Kills
The bacterium itself doesn’t usually deliver the fatal blow directly. Instead, it sets the stage for a cascade of problems. The most common cause of death is secondary bacterial pneumonia, a lung infection that takes hold after the initial whooping cough infection has already weakened the airways. This complication strikes about 17% of infants younger than six months.
Beyond pneumonia, the violent coughing fits create their own dangers. Pressure from severe coughing spasms can cause a collapsed lung, bleeding in the brain, hernias, or broken ribs. The toxin produced by the bacterium can also directly damage the nervous system, leading to seizures or swelling in the brain. In very young infants, the pattern is different: instead of dramatic coughing fits, the baby may simply stop breathing repeatedly, with little or no cough at all.
Risk for Older Adults
While deaths in healthy adults are rare, older adults with lung conditions face a more serious threat. People with COPD are three to four times more likely to contract whooping cough than the general population, and those with asthma are five to eight times more likely. In these groups, the infection can trigger severe flare-ups of their underlying disease, leading to hospitalization and potentially dangerous respiratory failure. The prolonged coughing, which can last 10 weeks or more, is also harder on aging bodies: rib fractures, fainting spells, and urinary incontinence are common complications in adults.
Warning Signs of a Dangerous Case
In babies, the most critical warning sign is apnea. If an infant pauses breathing, goes limp, or turns blue or pale around the lips and fingertips (cyanosis), that signals an emergency. These episodes can happen with little warning and sometimes before the classic “whoop” sound ever develops.
In older children and adults, watch for coughing fits so intense that the person vomits, can’t catch their breath, or briefly loses consciousness. A high fever alongside whooping cough symptoms may signal that pneumonia has developed. Rapid breathing, chest pain between coughing fits, and visible rib retractions (skin pulling in between the ribs with each breath) all point to worsening disease.
How Vaccination Changes the Odds
Vaccination is the single most effective tool for preventing whooping cough deaths. When pregnant women receive the Tdap vaccine during the third trimester, it prevents 78% of whooping cough cases in infants younger than two months and is 91% effective at preventing cases severe enough to require hospitalization. The antibodies cross the placenta and give newborns a shield during the vulnerable weeks before they can start their own vaccine series at two months old.
The childhood vaccine series (given at 2, 4, 6, and 15 to 18 months, with a booster before kindergarten) dramatically reduces the chance of severe illness. Protection does fade over time, which is why preteens get a booster around age 11 or 12, and why outbreaks still occur in older teens and adults. But even when a vaccinated person catches whooping cough, the illness tends to be shorter, milder, and far less likely to cause the dangerous complications that lead to death.
The pattern in recent outbreaks is consistent: the infants who die are overwhelmingly unvaccinated, and their mothers were not vaccinated during pregnancy. Keeping up with boosters also matters for the adults around a new baby, since older family members are often the ones who unknowingly bring the infection home.