Introduction 

Pertussis is the medical term for whooping cough and is a highly contagious infection of the respiratory system. It is caused by a bacteria called Bordetella pertussis. Before the introduction of the vaccine in the 1950s whooping cough was one of the most common childhood diseases across the globe. 

In this article we will go through what Pertussis is, the symptoms and the recommended vaccine schedules for the UK.

Symptoms of Pertussis 

• Initial catarrhal stage
• Irritating cough that becomes more intense and prolonged.

These 2 symptoms are usually within 1 - 2 weeks.

The following symptoms occur after the initial symptoms and can occur for 2 - 3 months

• Episodes of coughing that have a characteristic whoop and the patient can vomit during these episodes.
• In young babies and children the coughing spasms can lead to a bout of apnea (absence of breathing).
• Older children and adults may only have a persistent cough.

Complications of pertussis

Bronchopneumonia can occur along with prolonged vomiting episodes, weight loss and cerebral hypoxia (lack of oxygen to the brain).

Severe complications and deaths occur most commonly in infants under six(6)months of age.¹

Transmission of pertussis

Whooping cough is transmitted from an infected person to a susceptible one by droplets. In its early stages, it is highly contagious. Untreated patients can be contagious from 6 days after exposure to the infection and up to 3 weeks after the onset of symptoms. The incubation period(the time it takes for the disease to manifest) can be between 6 - 20 days after first contact with the infection.

Pertussis vaccine

The pertussis vaccine was introduced in the UK in the 1950s when the average number of cases in England and Wales would exceed 120,000 a year. By 1972 the average yearly case numbers had fallen to 2069 with 80% of children receiving the vaccine.

During a 2012 outbreak, the highest number of cases were in infants younger than 3 months of age, which is the age when infants receive their Pertussis vaccine in the UK immunisation schedule. A maternal immunisation programme was started that saw pregnant women vaccinated between 28 - 32 weeks of their pregnancy. Up to October 2014, there were 10 deaths reported in infants with confirmed whooping cough who were born after the maternal immunisation programme had started. Nine of these 10  babies who diedwere born to unvaccinated mothers.¹

The vaccine remains the best form of prevention of this disease.

Types of pertussis vaccine

The pertussis vaccine is acellular which means it includes purified components of the bacteria that cause whooping cough, rather than the whole bacteria cells. This means the vaccine can not cause whooping cough in the person receiving the vaccine. 

The UK's primary immunisation program combines the pertussis vaccine with 3 to 4 other vaccines in the same injection. According to the World Health Organisation, the acellular pertussis vaccine provides higher protection when given with 3 or 5 other vaccines at the same time, compared to when it is given with fewer vaccines.² 

Recommended vaccination schedule for children

The following table shows the age when a child should receive their Pertussis vaccine in the UK as a preschool booster

The First three doses of the vaccine will be given to the child before their first birthday in a schedule of 3 doses with a month gap between them. 

A fourth dose is given as a preschool booster to ‘top-up’ the doses given as a baby, as some baby immunisations protection can fade over time.³

Recommended vaccination schedule for adults

Even though routine vaccination against Pertussis for adults is not available in the UK, it is recommended that all pregnant women are offered a Pertussis vaccine. The immunity the mother builds up from the vaccine is passed through the umbilical cord to the fetus and this passive immunity will protect the baby until they can receive their first dose of the Pertussis vaccine themselves at 8 weeks old.

The vacine should be offered between 16 and 32 weeks of pregnancy to provide the highest level of protection to the baby upon birth. It has, however become best practice to offer the vaccine following the 20 week fetal anomaly scan which is at 20 weeks. The vaccine can be given later than 32 weeks of pregnancy, but the level of protection may not be as high. However, later vaccination does protect the mother from infection, which in turn prevents her from passing the infection on to her newborn.

In a study carried out in 2014 the BMJ (British Medical Journal) found that there were no adverse effects to mother or baby following the admisinstreration of the Pertussis vaccine to the mother.⁴

Importance of adherence to the schedule

Vaccinating children who are eligible to receive the pertussis vaccine helps protect vulnerable members of our communities from the infection. The transmission occurs from an infected perso. By vaccinating 90% of the community, we can reduce the number of infected people that vulnerable individuals may come into contact with.

Summary

Pertussis, also known as whooping cough, has in recent years become a public health concern again despite the UK Immunisation Scehdule.  The disease can cause severe complications in young infants. The UK Vaccinations Schedule recommends babies receive their first dose of the Pertussis vaccine at 8 weeks old, followed by two more doses given a month apart. A fourth booster dose is given at pre-school age, which should protect them through school years. Recent outbreaks have highlighted the need for paternal immunisation to protect newborns. Adhering to the recommended vaccination schedules for children and pregnant mothers is crucial. High community vaccination rates not only protect vaccinated individuals but also contribute to herd immunity, safeguarding those who are too young or otherwise unable to be vaccinated.