There is a particular cruelty to whooping cough. It begins so modestly that it is easy to dismiss: a runny nose, a mild fever, an ordinary cough that could belong to any winter virus. Then the rhythm changes. The cough hardens into paroxysms, the child retches or gasps, and the room itself seems to tense with every desperate inhalation. In infants, the illness may not even grant the theatrical honesty of a “whoop”; it may present instead as apnoea, cyanosis, exhaustion, or a silence that is more frightening than noise. Pertussis is one of those infections that modern medicine has pushed to the margins, but never quite out of the frame. And when it returns, it reminds us how fragile that distance has always been.[1,2]
Whooping cough, or pertussis, is caused primarily by Bordetella pertussis, a fastidious Gram-negative coccobacillus spread through respiratory droplets. It is highly contagious, and although it can affect any age group, its most severe burden still falls on the youngest patients, especially infants too young to have completed their primary immunisation series.[1,3] The clinical course is classically divided into catarrhal, paroxysmal, and convalescent phases: first a nonspecific coryzal illness, then the violent coughing fits with post-tussive vomiting or inspiratory whoop, and finally the long, weary tapering of symptoms over weeks to months. The old phrase “the hundred-day cough” survives for a reason.[1,4]
Why pertussis deserves our attention again
Pertussis is not merely a historical curiosity, nor simply a paediatric nuisance. In severe infant disease it can cause pneumonia, seizures, encephalopathy, pulmonary hypertension, profound leucocytosis, respiratory failure, and death.[3,5] The infants who deteriorate fastest are often the very ones least protected: newborns and young babies who have not yet had time either to be vaccinated themselves or to benefit sufficiently from household immunity. In that sense, pertussis remains an unusually revealing disease. It exposes not only the vulnerability of the infant, but the degree to which the adults around that infant have maintained — or neglected — the ordinary disciplines of prevention.[3,5,6]
In recent years, pertussis has again attracted concern because several countries have reported substantial rebounds following the COVID-19 period, with increases noted even in settings with high primary vaccine uptake.[2] Part of this reflects the predictable rebound after years of altered respiratory virus transmission, but it also draws attention to an older and more difficult truth: pertussis control has always been more complex than many other vaccine-preventable diseases. The organism continues to circulate, immunity wanes, and surveillance often captures only part of the true burden, especially in adolescents and adults whose illness may present as nothing more than an exhausting, persistent cough.[2,7]
Why pertussis comes back, even in vaccinated societies
The resurgence of pertussis in highly vaccinated populations has been studied for years, and the explanations are layered rather than singular. One of the most important is waning immunity, particularly after acellular pertussis vaccination. Acellular vaccines were introduced because they are safer and better tolerated than the older whole-cell products, but they do not appear to induce immune responses of quite the same durability or breadth. Immunological and epidemiological studies suggest that protection after acellular vaccination can decline substantially within a few years, especially after boosters, allowing older children, adolescents, and adults to become susceptible again.[7]
That does not mean pertussis vaccines do not work. They do. Rather, it means that pertussis vaccines do not produce the sort of long, serene immunity that encourages complacency. This is part of why boosters matter, and why maternal vaccination has become such a central strategy. It also helps explain why adults, who may experience only a prolonged cough without classic whooping, can still serve as reservoirs of transmission to infants.[7,8] Pertussis is therefore not simply a story of vaccine success or vaccine failure. It is a story of partial control over a pathogen that remains biologically capable of exploiting every lapse in timing, coverage, or memory.[7,8]
There are other contributing factors as well. Improved awareness and better molecular diagnostics have made case detection more sensitive in some settings. Antigenic changes in circulating B. pertussis strains may also influence how well existing vaccine-induced immunity performs. And, as with several respiratory infections, the pandemic period altered both transmission patterns and immunity gaps in ways that are still being fully understood.[2,9] The result is not one single cause of pertussis resurgence, but a convergence of biological drift, waning immunity, diagnostic visibility, and public health disruption.[2,9]
The most important prevention strategy: vaccination
For all the nuance, the centre of the story remains simple: vaccination is still the cornerstone of pertussis prevention. Routine childhood immunisation reduces disease, hospitalisation, and death, even if it does not eliminate transmission altogether.[7,8] The practical challenge is that protection must be layered. Infant primary series matter. Preschool and adolescent boosters matter. Adult boosters in relevant settings matter. And above all, maternal vaccination during pregnancy matters because it protects the infant during the earliest and most dangerous weeks of life, before the baby’s own schedule is complete.[6,8,10]
Maternal vaccination is one of the clearest advances in modern pertussis prevention. The principle is elegant: vaccinate during pregnancy so that maternal antibodies cross the placenta and protect the newborn during those first precarious months. The evidence supporting this strategy is now strong. Case-control and systematic review data suggest high effectiveness in preventing pertussis in young infants, as well as a reassuring safety profile.[6,10,11] In practical terms, this means that when we talk about protecting babies from whooping cough, we are often really talking about vaccinating the pregnant person on time.[6,10,11]
Timing during pregnancy has also been studied closely. While national recommendations differ, the purpose is consistent: maximise antibody transfer before birth without missing the window.[10,11] This is one reason why pertussis vaccination in pregnancy should not be treated as an optional afterthought or something that can be “caught up” vaguely later. In many cases, the infant’s first protection depends on decisions made before the infant is born.[10,11]
What about cocooning?
Before maternal immunisation was widely adopted, much attention was given to “cocooning” — vaccinating parents, siblings, grandparents, and close caregivers around a newborn. The logic remains sound: if the people nearest the infant are immune, the infant is less likely to be exposed. But real-world implementation has been difficult. Coverage is inconsistent, logistics are messy, and evidence for population-level impact has been less compelling than once hoped.[6,12] Cocooning is therefore best understood as an adjunct, not a replacement, for maternal vaccination and routine childhood immunisation.[6,12,13]
That said, the core moral intuition behind cocooning still matters. Pertussis prevention is not an individual performance. Infants depend on concentric layers of protection created by others: the pregnant mother receiving Tdap at the right time, the household being up to date, the community maintaining childhood vaccine coverage, and clinicians recognising illness early enough to limit spread. The baby is at the centre, but the protection is collective.[6,12,13]
How pertussis is treated
Once pertussis is suspected or confirmed, antibiotics are used primarily to eradicate the organism from the nasopharynx and reduce onward transmission. Their effect on symptoms depends heavily on timing. If given early, during the catarrhal phase, they may blunt the course of illness. Once the paroxysmal phase is fully established, however, antibiotics usually do not dramatically shorten the coughing illness itself.[4,14,15] This is one of the frustrations of pertussis: by the time the diagnosis becomes clinically obvious, some of the therapeutic window has already narrowed.[4,14,15]
Macrolides remain the mainstay of treatment and post-exposure prophylaxis. Azithromycin and clarithromycin are generally preferred for tolerability and convenience, while erythromycin is used less often because of gastrointestinal adverse effects and concerns such as infantile hypertrophic pyloric stenosis in very young infants.[14,15] Shorter macrolide regimens have been shown to be as effective microbiologically as longer erythromycin courses, with fewer side effects.[15] For patients in whom macrolides cannot be used, trimethoprim-sulfamethoxazole may be an alternative in appropriate age groups.[14,15]
In severe infant pertussis, antibiotics alone are not enough. These are the cases in which supportive care becomes the real centre of management: oxygen, hydration, feeding support, close cardiorespiratory monitoring, and, in critical illness, intensive care.[3,5] Infants with marked hyperleucocytosis and pulmonary hypertension may require exchange transfusion or blood exchange procedures, not because these are elegant therapies, but because severe pertussis can become a disease of mechanical circulatory compromise as much as infection.[3,5]
Why early recognition still matters
Pertussis is often under-recognised in adolescents and adults because its presentation can be deceptively unspectacular. Not every patient who has pertussis produces the classic whoop. Many will simply have a persistent cough, perhaps with vomiting after fits, perhaps worse at night, perhaps lingering far beyond the point when ordinary viral bronchitis should have resolved.[1,8] The clinical importance of recognising this lies not only in treating the patient, but in identifying who else may be at risk — especially newborns, pregnant household members, and other vulnerable contacts.[1,8,14]
That is why public health measures remain essential. Suspected or confirmed cases may require exclusion from school, childcare, or healthcare work until they are no longer considered infectious. Close contacts, particularly those at high risk, may need prophylactic antibiotics.[14] In the modern clinic, the task is not only to manage pertussis as an individual illness, but to remember that it is still a transmissible household and community event.[14]
What patients should understand
Patients do not need to be frightened into respecting pertussis, but they do need a more mature explanation than the old assumption that whooping cough is simply a rough childhood cough. It is a preventable respiratory infection that remains capable of causing prolonged illness in adults and life-threatening disease in infants.[1,3] Vaccination does not make pertussis disappear from the world, but it reduces its burden, shifts its severity, and offers the youngest patients a chance not to meet the disease at its worst.[6,7,10]
The most important message is perhaps the least dramatic one. Pertussis control is not sustained by panic, but by routine: vaccinating on schedule, boosting when indicated, vaccinating in pregnancy, recognising symptoms early, and taking public health advice seriously when exposure occurs. These are ordinary acts. But for an infant not yet old enough to defend itself, ordinary acts can be the difference between a difficult cough in the family and an intensive care admission in the night.[3,6,10]
References
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[2] González-López JJ, Vázquez-Morón S, García-Cisneros S, et al. Epidemiology, prevention and control of pertussis in Spain: new vaccination strategies for better control. Enferm Infecc Microbiol Clin (Engl Ed). 2022;40(10):534-542.24Please respect copyright.ＰＥＮＡＮＡnR3gB96aYi
[3] Principi N, Esposito S. Pertussis epidemiology in children: the role of maternal immunization. Pathogens. 2024;13(9):783.24Please respect copyright.ＰＥＮＡＮＡUk302ujAvy
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[6] Godoy P, García-Cenoz M, Rius C, et al. Effectiveness of maternal pertussis vaccination in protecting newborn: a matched case-control study. J Infect. 2021;83(5):554-558.24Please respect copyright.ＰＥＮＡＮＡzKt6cGyh9i
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[8] Olson-Chen C, Healy CM, Rench MA, et al. The current state of pertussis vaccination in pregnancy around the world, with recommendations for improved care: consensus statements from the Global Pertussis Initiative. Int J Gynaecol Obstet. 2024;165(3):860-869.24Please respect copyright.ＰＥＮＡＮＡsioDRKLeoO
[9] Kandeil W, Atanasov P, Avramioti D, Fu J, Demarteau N, Li X. A systematic review of the burden of pertussis disease in infants and the effectiveness of maternal immunization against pertussis. Expert Rev Vaccines. 2020;19(7):621-638.24Please respect copyright.ＰＥＮＡＮＡquhqiCO0gu
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[11] Wijngaard CC, Warris LT, Perquin DAM, et al. Timing of pertussis vaccination during pregnancy. Vaccine. 2024;42(39):126514.24Please respect copyright.ＰＥＮＡＮＡOsqLUVD6Kf
[12] Grizas AP, Camenga DR, Vázquez M. Cocooning: a concept to protect young children from infectious diseases. Curr Opin Pediatr. 2012;24(1):92-97.24Please respect copyright.ＰＥＮＡＮＡZQjg80wAol
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[14] Tiwari T, Murphy TV, Moran J; National Immunization Program, CDC. Recommended antimicrobial agents for the treatment and postexposure prophylaxis of pertussis: 2005 CDC guidelines. MMWR Recomm Rep. 2005;54(RR-14):1-16.24Please respect copyright.ＰＥＮＡＮＡFOU3WfCEMn
[15] Altunaiji S, Kukuruzovic R, Curtis N, Massie J. Antibiotics for whooping cough (pertussis). Cochrane Database Syst Rev. 2007;(3):CD004404.
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Disclaimer:24Please respect copyright.ＰＥＮＡＮＡHwyg6rZvaG
The information in this article is for general information and educational purposes only. It is not a substitute for independent professional medical advice, diagnosis, or treatment. Always consult a suitably qualified healthcare professional with any questions or concerns about your health or a medical condition. Never ignore, delay, or disregard professional medical advice because of something you have read in this article.24Please respect copyright.ＰＥＮＡＮＡBUjx22ffWX
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