Information about pertussis (whooping cough)

Pertussis (whooping cough)


Pertussis (whooping cough) is a bacterial infection that primarily affects the lungs, causing a cough.  The illness begins with a catarrhal stage which could be mistaken for the cough that accompanies a common cold. (This is the stage at which the disease is most infectious; pertussis is considered to be contagious from three weeks after the onset of coughing.)

Some (not all) people who contract pertussis have a cough which has a characteristic “whooping” sound.

(Children are more likely to have the classic “whooping” noise when they cough than are babies or adults. Babies may not have obvious coughing at all but may suffer from breathing difficulties, including apnoea.)  The coughing fits may be accompanied by vomiting and the combination of these symptoms can be quite debilitating. In severe cases, the patient may become temporarily blue from oxygen deprivation at the end of a coughing fit.

There is a risk of developing pneumonia as a complication.  A less common but very serious complication is encephalitis (inflammation of the brain) which may cause brain damage (or be fatal).

Untreated pertussis may last for 100 days as the immune system can take a long time to bring the bacterial infection under control. After a bout of pertussis, people may remain vulnerable to other chest infections for some months until their lungs have fully recovered from the effects of the bacteria.

Pertussis is most dangerous to babies under six months of age due to their smaller airways and immature immune systems. When deaths occur in NZ from pertussis they are usually in young infants.  (Fortunately deaths from pertussis are rare; about one child per year.)

The most recent information available about pertussis incidence in NZ from the ESR website is below:

Immunity after a pertussis infection is thought to last about 25-30 years.


Control of pertussis

Vaccination is the main strategy used in NZ to try to reduce the number of cases of pertussis and deaths from the disease.  (See the section on pertussis vaccination, below, for information about the different pertussis vaccines available on the NZ market and the age at which they are recommended.)

It was hoped when vaccination against pertussis was first developed that the vaccines would reliably prevent the disease and its complications; however, pertussis has persisted in NZ despite widespread vaccination.  (An overview of pertussis cases and deaths from the 20th century onwards may be read at this link: )

Antibiotic treatment may be used to reduce the risk of spreading the infection to others.

The current antibiotic treatment recommendations may be found at the link below:




In NZ, pertussis (whooping cough) vaccination is free for babies and children, and in some situations for adults.

The current vaccines available on the NZ market use an acellular form of pertussis vaccine and there is concern that this vaccine is less effective than the “whole cell” pertussis vaccine.

(The whole cell pertussis vaccine is no longer used in developed countries due to concern about side effects, including brain damage, from this type of pertussis vaccine.)

For babies in NZ, pertussis vaccination is available as part of a combined vaccine (which also includes hepatitis B, polio. diphtheria tetanus and Haemophilus influenza type B components) called Infanrix-hexa. This vaccine is on the national schedule for babies of six weeks, three months and five months of age. The datasheet (prescribing information) for this vaccine may be read at this link:

This vaccine is recommended for babies of this age by the NZ Ministry of Health, however, parents can choose to delay vaccinations if they so choose or decide against their babies having any vaccinations.

Most babies in NZ are vaccinated with Infanrix-hexa; almost 93% of eight month old babies were fully vaccinated for their age (that is, in accordance with the current Ministry of Health recommended vaccination schedule) in the 12 month period ending September 2016

Booster shots that contain a pertussis component that are also free for children in NZ include the INFANRIX™-IPV vaccine recommended for children of four years (which also includes polio, diphtheria, and tetanus components) and  BOOSTRIX™ which is on the schedule for 11 year olds. (Boostrix includes diphtheria and pertussis components in addition to pertussis.) The datasheets for these vaccines are and

Many adults are vulnerable to pertussis infection – either because they were vaccinated in childhood and their vaccine-induced immunity has waned or because immunity after a natural pertussis infection lasts only 25-30 years.

Pregnant women in NZ are now offered pertussis vaccination (as part of a combined vaccine that also contains diphtheria and tetanus components) in the third trimester in an effort to prevent severe pertussis in infants who are too young to be vaccinated.

The NZ Ministry of Health claims that vaccination during pregnancy is safe. Another perspective on pertussis vaccination in pregnancy (written by a doctor) may be read at this link:


Treatment of pertussis


  • Antibiotics

Treatment with specific antibiotics may be recommended. (The current antibiotic treatment options are discussed at this link:  However, while treatment with antibiotics has the benefit of reducing the risk of transmitting the infection to others, antibiotic treatment is not likely to alter the course of the disease for people who are already ill with pertussis unless treatment begins at the catarrhal stage of the illness.

  • Vitamin C

High doses of supplementary vitamin C may be used to treat pertussis.  Like antibiotics, this treatment is more likely to be successful if it is begun in the catarrhal stage of the illness.  The reason for this is that pertussis bacteria produce a toxin that damage the cilia (the finger-like projections of the cells that line the lungs that help to “waft” dust, mucus etc. up and out of the lungs).  High doses of vitamin C early in the course of the illness can help to neutralise the toxin produced by the pertussis bacteria and thus reduce damage to the cilia.

Supplementary vitamin C is generally a very safe treatment unless the patient has a rare genetic disorder (for example G6PD deficiency) that makes the use of high dose vitamin C potentially dangerous.

An article by a medical doctor about the use of vitamin C in the treatment of pertussis is here.

Please note that given the potentially serious complications of pertussis it is recommended that this treatment should be considered for use under the supervision of a health professional rather than attempting self-treatment.



Website editor’s note: Please note that information on this website is for educational purposes only and is not intended to replace a consultation with a competent health professional who is aware of the patient’s personal and family medical history and other relevant factors and therefore can assist in making an informed choice regarding vaccination or treatment.

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