Whooping cough, a vaccine-preventable disease many parents associate with history books, is roaring back in parts of the United States. Several states are reporting their highest case counts in years, forcing health departments to reopen outbreak playbooks that had gathered dust through the COVID era.
This resurgence is colliding with pandemic-era disruptions in routine immunization, uneven booster uptake among adolescents and adults, and a pathogen already known for slipping past imperfect vaccines. The result is a respiratory infection once again filling pediatric clinics and contact-tracing spreadsheets.
How pertussis quietly rebuilt momentum after the pandemic lull
Public health officials expected some rebound in respiratory infections once COVID restrictions eased, but the scale of pertussis activity in several states has surprised them. During the height of masking, school closures, and social distancing, reported whooping cough cases plunged to historic lows as Bordetella pertussis lost its usual pathways from child to child. When those protections fell away, the bacterium encountered a population that had missed routine shots, skipped boosters, or aged out of early childhood immunity.
Wisconsin illustrates the pattern. State data show that reported pertussis infections have climbed to the highest levels in years, with clusters stretching from Milwaukee suburbs to smaller school districts. Health officials there have mapped cases against immunization records and found pockets of under-vaccination in both urban neighborhoods and rural counties, a sign that the problem is not limited to one demographic or geography. Local clinics have responded by extending hours and setting up additional vaccination sites so families can catch up on missed doses.
Earlier disruptions in pediatric care are a major part of the story. During the COVID years, many parents postponed well-child visits where infants and toddlers would normally receive the DTaP series that protects against diphtheria, tetanus, and pertussis. National immunization surveys have documented that some children never made up those appointments. That left a larger-than-usual cohort of preschoolers and early elementary students without full protection, a perfect fuel source once pertussis re-entered classrooms and daycare centers.
Meanwhile, immunity among teenagers and adults has continued to wane. The acellular pertussis vaccines used in the United States are much safer than the older whole-cell versions, but they do not provide lifelong protection. Studies have shown that effectiveness declines within a few years of the last dose, which means adolescents who received their Tdap booster in middle school may offer little barrier to transmission by the time they reach college or the workforce. In communities where adult booster uptake is low, pertussis can circulate quietly and then land on infants who have yet to complete their primary series.
Wisconsin health leaders have highlighted how this combination of missed early shots and fading booster protection has produced the current spike. In some counties, more than half of recent cases have occurred in school-age children who were either behind on vaccines or had not received the recommended Tdap dose. Others involve parents and caregivers with only mild coughs who later tested positive after infants in the household became severely ill.
Why the current wave of whooping cough demands attention
The renewed spread of pertussis is not only a story about case counts. It is a warning about how quickly a familiar pathogen can regain ground when vaccination coverage slips and surveillance systems are stretched. For infants younger than 6 months, who cannot yet rely on a complete vaccine series, the stakes are particularly high. Pertussis in this age group can cause pneumonia, seizures, and life-threatening episodes in which the baby stops breathing and turns blue.
Clinicians in states with rising activity report that hospitalizations have started to climb, especially among very young infants and those with underlying conditions like prematurity or chronic lung disease. Many of these babies were infected by older siblings or adults who experienced only a nagging cough. Because pertussis often presents like a common cold in vaccinated teenagers and adults, it can circulate for weeks before anyone thinks to test, giving the bacterium ample time to reach more vulnerable family members.
The trend also carries policy implications. Persistent pockets of low vaccination coverage have become a flashpoint in debates over school immunization requirements and medical or religious exemptions. In some districts, administrators are now sending exclusion notices to unvaccinated students who are identified as close contacts, a step that can keep children out of classrooms for weeks. Families who previously viewed pertussis as a theoretical risk are confronting the practical consequences of those choices when their child is told to stay home during an outbreak.
On the public health side, the resurgence is straining already thin staffing. Contact tracers who had shifted away from COVID investigations are now following chains of exposure in schools, sports teams, and daycare centers. Local health departments must balance pertussis response with influenza, RSV, and coronavirus monitoring as respiratory viruses stack on top of one another. Each suspected pertussis case triggers a cascade of phone calls, prophylactic antibiotic prescriptions, and decisions about who should be temporarily excluded from group settings.
The Wisconsin experience underscores how quickly these demands can escalate. As reported case numbers climbed, state officials published updated guidance for clinicians, expanded access to testing, and promoted locations where families could receive Tdap or DTaP vaccines. An overview of recent Wisconsin cases describes how health departments are coordinating with schools and childcare centers to identify exposures and offer on-site vaccination clinics.
Beyond immediate illness, pertussis flare-ups expose broader vulnerabilities in the immunization safety net. When a disease that is both preventable and long familiar begins to surge, it raises questions about whether communities are prepared for the reappearance of other vaccine-preventable infections. Measles, which is even more contagious, has already re-emerged in some areas with declining childhood vaccination rates. Pertussis adds another pressure point and may force policymakers to revisit funding for immunization outreach, school-based clinics, and adult booster campaigns.
How states and communities can respond to sustained pertussis pressure
Given the biology of Bordetella pertussis and the characteristics of current vaccines, health experts do not expect the bacterium to disappear. The realistic goal is to keep it from reaching infants and those at highest risk of severe disease. Achieving that requires a mix of catch-up vaccination, targeted booster strategies, and sharper clinical awareness.
One immediate priority is restoring routine childhood vaccination coverage to pre-pandemic levels or better. Pediatric practices and community health centers are using reminder systems, school partnerships, and weekend clinics to help families close gaps in the DTaP schedule. Some states are tying back-to-school paperwork to up-to-date immunization records, which nudges parents to schedule appointments before the academic year begins. In areas with transportation or access barriers, mobile clinics and pop-up sites at community centers, churches, and food pantries can make a significant difference.
Another key layer is maternal vaccination. Pregnant people who receive Tdap in the third trimester pass protective antibodies to their babies, which can shield infants during the first vulnerable months of life. Obstetric providers are being urged to treat Tdap as a standard part of prenatal care, similar to influenza and COVID vaccination. When combined with timely infant doses, this strategy creates a buffer that can blunt the worst outcomes even if pertussis continues to circulate in the community.
For adolescents and adults, public health agencies are exploring ways to normalize periodic Tdap boosters, especially for those who live with or care for young children. Employers in childcare, healthcare, and education settings can play a role by offering on-site vaccination or including Tdap in occupational health requirements. Pharmacies, which already deliver large volumes of influenza and COVID shots, are well positioned to offer opportunistic Tdap doses when people come in for other vaccines.
Clinicians also have a part to play in recognizing pertussis earlier. Because early symptoms mimic a cold, providers may not immediately think of whooping cough in a vaccinated teenager or adult. Updated advisories in hard-hit states encourage doctors to test and treat anyone with a prolonged cough, especially if they have contact with infants or work in group settings. Prompt diagnosis can trigger faster prophylaxis for close contacts and limit spread.
