Whooping cough: what the cough sounds like and what to do
Whooping cough is one of those illnesses most people consider a thing of the past, yet it still circulates and causes outbreaks in the UK, and it can be genuinely life-threatening in young babies. Knowing what it sounds and looks like, why young babies behave differently, and when to call for emergency help could make a real difference.
What is whooping cough?
Whooping cough (also called pertussis) is a bacterial infection of the respiratory tract caused by Bordetella pertussis. It infects the airways, triggering severe, prolonged coughing fits that can last for months. Despite widespread vaccination programmes in the UK and many other countries, it still circulates and causes outbreaks, particularly in communities where vaccination rates dip.
It can be a mild, manageable illness in older children and adults, but it can be very serious, and even life-threatening, in young babies who have not yet completed their vaccination course. According to NHS data, the majority of serious complications and deaths from whooping cough in the UK occur in babies under three months.
Why whooping cough is still a risk
Vaccination greatly reduces risk but does not eliminate it entirely. Two things matter here. First, vaccine immunity wanes over time. Older children who were vaccinated as babies, and adults vaccinated decades ago, can lose sufficient protection to contract and spread the infection. They may experience it as a prolonged, irritating cough rather than anything dramatic, and many never realise they have it.
Second, your newborn baby has no protection of their own until their vaccine course begins at eight weeks, and does not have full protection from three doses until around four months of age. During that window, an unrecognised case of whooping cough in an older sibling, a grandparent, or another household member is the most common way it reaches a young baby. During outbreaks, even vaccinated family members can carry and transmit the infection.
This is why the maternal whooping cough vaccine in pregnancy is so important: it is designed to bridge exactly this gap.
What the cough sounds, and looks, like
The illness begins like a cold. For one to two weeks your baby or child will have a runny nose, mild fever, and an ordinary-seeming cough. This cold-like phase is actually when the illness is most contagious, which is one reason it spreads so effectively before anyone suspects what it is.
Over the following week or two, the cough worsens dramatically. It becomes severe and uncontrollable, arriving in long, rapid bursts that can last 30 seconds or more. At the end of a long coughing fit, older children and adults often make the distinctive sound that gives the illness its name: a high-pitched, gasping whoop as they suddenly draw breath after the prolonged coughing. Vomiting after coughing fits is also very common. The cough can last for months, which is why it is sometimes called the "100-day cough."
The cough typically sounds much worse at night. Some children go red or purple in the face during a fit, which is frightening to witness but is caused by the sustained effort of coughing rather than by airway obstruction.
Why babies behave differently
This is the most important thing to understand about whooping cough in young babies: they often do not make the classic whooping sound at all. Young babies do not have the muscle strength or the vocal cord development to produce the whoop. Instead, when a prolonged coughing fit exhausts their small airways, the airway simply closes off.
What you may see instead: your baby going blue around the lips or turning a pale grey colour during or after a coughing fit (cyanosis); your baby becoming completely limp or floppy; your baby stopping breathing entirely for several seconds (apnoea). These are emergency signs. They indicate that your baby's body is not managing the coughing fit safely.
The absence of the whoop in young babies makes whooping cough harder to recognise, and it is one reason parents and even healthcare professionals can initially mistake it for another illness. If your young baby has a cough and shows any colour change, limpness, or breathing pause during or after it, do not wait to see if it resolves. Call 999.
Vaccine protection
The UK vaccine schedule offers protection at two layers. The maternal whooping cough vaccine, offered to pregnant women between 16 and 32 weeks of pregnancy, causes the mother's body to produce antibodies that are then transferred to the baby through the placenta before birth. These maternal antibodies give the baby passive protection from birth, covering the critical early weeks before their own vaccination can begin. NHS data shows that maternal vaccination significantly reduces the risk of whooping cough in young babies and substantially reduces the risk of serious illness and death.
Babies then begin their own vaccination course as part of the 6-in-1 vaccine at eight weeks, with further doses at 12 weeks and 16 weeks. Three doses are needed for good protection. Booster doses are given later in childhood. If you were not vaccinated during pregnancy, it is worth speaking to your GP or health visitor about the best way to protect your baby, and whether vaccination of close family members is appropriate.
When to call 999
Call 999 immediately, without delay, if your baby:
- Goes blue around the lips, or turns a pale grey colour, during or after a coughing fit.
- Stops breathing, or has a long pause in breathing, during or after a coughing fit.
- Becomes completely limp or unresponsive after a coughing fit.
- Is working very hard to breathe between coughing episodes: you can see the muscles around their neck and between their ribs pulling in, or their nostrils flaring with each breath.
These are not "see how it goes" symptoms. They require emergency help immediately.
Treatment and quarantine
Whooping cough is treated with antibiotics, usually azithromycin or clarithromycin. Antibiotics given early in the illness (within two to three weeks of the cough starting) can reduce how contagious you are to others and may shorten the illness itself. If antibiotics are started after that window, they are still worth taking because they reduce the risk of spreading the infection to vulnerable contacts, even if the cough itself has to run its course.
Whooping cough is a notifiable disease in the UK, meaning doctors are required to report confirmed cases to the local health protection team. Infected individuals should stay away from babies, young children, and childcare for 48 hours after starting antibiotics, or for 21 days from the start of the cough if antibiotics are not taken.
If someone in your household is diagnosed and you have a young unvaccinated or partially vaccinated baby, your GP may offer preventive antibiotics to your baby. This is called post-exposure prophylaxis and can reduce the chance of your baby developing the illness.
Frequently asked questions
What does whooping cough sound like in a baby?
In older babies and children it sounds like a long burst of rapid coughing followed by a high-pitched intake of breath, the whoop. In young babies under six months you may not hear the whoop at all. Instead you may see colour change (going blue or grey), limpness, or pauses in breathing after coughing fits. If you see any of these signs in your young baby, call 999 immediately.
Why don't young babies make the whoop sound?
Young babies do not have the muscle strength or vocal cord development to generate the whoop. Instead, their airways simply close off, causing apnoea (breathing pauses) or cyanosis (colour change). This is why whooping cough is both more dangerous and harder to recognise in the youngest babies.
How long does whooping cough last?
It is often called the 100-day cough for a reason. Severe coughing fits typically last six to ten weeks, with gradual improvement. Even after the worst has passed, the cough can continue for months. A course of antibiotics does not make the cough go away faster once it is established, but it stops you spreading the infection to others.
When does my baby get the whooping cough vaccine?
In the UK, babies receive their first dose of pertussis-containing vaccine at eight weeks, with further doses at 12 weeks and 16 weeks. The maternal vaccine offered in pregnancy between 16 and 32 weeks passes antibodies to your baby before birth, protecting them from birth until their own course begins.
Is my vaccinated baby protected?
Three doses give good protection, but no vaccine is 100% effective. If your vaccinated baby develops a persistent or unusual cough, it is still worth seeing your GP. Even if vaccinated babies do contract whooping cough, they tend to have milder illness than unvaccinated babies.
Can adults pass whooping cough to babies?
Yes. Adults and older children who had whooping cough or were vaccinated years ago can lose immunity and carry the infection with only mild symptoms, such as a prolonged irritating cough. This is how it most commonly reaches newborns. If anyone in the household has a cough lasting more than a few weeks, see your GP.
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