Whooping cough has killed two U.S. children this year as cases climb again

Two children have died of whooping cough in the United States so far in 2026, and health officials say the bacterial infection is once again working through its familiar seasonal climb. Federal surveillance data compiled through the late spring and early summer of 2026 put the national case count at 4,598, a tally that public health researchers say tracks closely with communities where routine childhood vaccination has slipped.

Bordetella Pertussis and the Cough That Won’t Quit

Whooping cough is caused by the bacterium Bordetella pertussis, which attaches to the tiny hairs lining the upper respiratory tract and releases toxins that damage tissue and trigger violent coughing fits. The illness gets its common name from the sharp, gasping “whoop” sound many patients make when they finally manage to inhale after a coughing spell, though very young infants often do not cough at all and instead stop breathing for short, frightening stretches.

Early symptoms mimic an ordinary cold, which is part of why the disease spreads so easily before anyone realizes what it is. According to Medical Daily’s review of the 2026 case data, both of this year’s confirmed pediatric deaths occurred in infants too young to have completed the primary vaccine series, a pattern that has held in nearly every fatal pertussis case recorded in the United States over the past two decades.

4,598 Cases and Two Confirmed Deaths

The 4,598 cases reported through the late-spring tally mark a real but uneven slice of what has become a boom-and-bust disease. The count sits well below the tens of thousands of cases logged during 2024 and 2025, when pertussis roared back after pandemic-era social distancing had suppressed it for several years, yet it is still enough to alarm pediatricians watching for the disease’s usual late-summer peak.

The Centers for Disease Control and Prevention’s pertussis surveillance program collects case reports from state and local health departments on a rolling basis, which is why national totals are typically revised upward for weeks after any given reporting date. That lag is also why public health officials caution against reading any single snapshot as the final word on how bad a given year will turn out to be.

Why Pertussis Cycles Every Few Years

Unlike measles, which can be nearly eliminated when vaccination coverage stays high enough, whooping cough follows a natural boom-and-bust rhythm even in well-vaccinated populations, with national case counts historically cresting every three to five years as immunity in the population wanes and a new pool of susceptible people builds up. Protection from both the childhood DTaP series and the adolescent and adult Tdap booster fades over time, which means even fully vaccinated teenagers and adults can catch and spread the bacteria, often with symptoms mild enough that they never realize they are contagious.

That waning-immunity pattern is precisely why infants, who have not yet received enough doses to be protected, depend heavily on everyone around them staying current on boosters, a strategy doctors call cocooning.

The Vaccination Gap Behind the Numbers

Public health researchers have flagged a slow but steady erosion in childhood vaccination coverage across a number of states in recent years, and pertussis is often the first disease to resurface when that coverage slips, since it circulates more easily than diseases like measles even at high vaccination rates. The standard schedule calls for five DTaP doses between two months and six years of age, followed by a single Tdap booster around age eleven, then further boosters for adults, including pregnant women in each pregnancy so that newborns inherit some antibody protection.

Pregnant women who receive Tdap in the third trimester pass protective antibodies to the fetus, a strategy the CDC specifically recommends because it shields infants during the first two months of life, before they are old enough for their own first dose.

Infants Under Two Months Face the Greatest Risk

Nearly all pertussis deaths in the United States occur in infants younger than three months, a window when a baby’s airways are narrow enough that even ordinary mucus and swelling can dangerously restrict breathing. Hospitalization rates for infected infants run far higher than for any other age group, and severe cases can lead to pneumonia, seizures, or the temporary breathing pauses known as apnea.

Pediatricians generally advise that any infant with a persistent cough, especially one accompanied by breathing pauses, gagging, or a bluish tint to the lips, be evaluated promptly rather than assumed to have an ordinary cold, since early antibiotic treatment can reduce how contagious a patient remains even after symptoms have set in.

How Schools and Daycares Factor Into Local Outbreaks

Because pertussis spreads through respiratory droplets released by coughing and talking, settings where young children spend hours in close proximity, such as daycare centers and elementary schools, have historically served as amplification points once a single case enters the building. Local health departments often respond to a confirmed pediatric case by notifying a school community and reviewing vaccination records, since even a handful of exempt or under-vaccinated students can be enough to sustain a chain of transmission.

That dynamic is part of why case counts in a given state can jump sharply within a matter of weeks once pertussis establishes itself in a school district, then taper off just as quickly once summer break interrupts the close contact that let it spread in the first place.

Context matters when reading any single-year pertussis number in isolation. The disease’s return to elevated levels in 2024 and 2025 followed several unusually quiet years during which pandemic-era masking and distancing suppressed a wide range of respiratory illnesses, pertussis included, and left a larger-than-usual pool of children without natural exposure or timely vaccination. That pent-up susceptibility is one reason researchers expected a rebound once ordinary social contact resumed, even before factoring in any decline in routine vaccination rates.

Viewed against that backdrop, 2026’s case count represents a partial cooling from the recent peak rather than an entirely new crisis, though the two pediatric deaths confirmed so far are a reminder that even a comparatively lower-case year can still carry the disease’s most serious consequences.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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