The World Health Organization describes immunisation as “the process where a person is made immune or resistant to an infectious disease, by the administration of a vaccine. Vaccines stimulate the body’s own immune system to protect the person against subsequent infection or disease”.

Immunisation is a proven tool for controlling and eliminating life-threatening infectious diseases worldwide. It is estimated to prevent up to three million deaths each year. 

This topic is designed to support primary healthcare professionals:

• To understand the range of diseases that can be prevented with immunisation

• To immunise all children who require protection from infectious disease

• To educate and inform parents, carers, and older children of the benefits of immunisation.

Diseases prevented by immunisation

Diphtheria

Diphtheria is an acute infectious disease caused by toxigenic strains of Corynebacterium diphtheriae and C. ulcerans. It causes a grey, thick, fibrinous membrane (pseudomembrane) to affect the upper respiratory tract.

Classical diphtheria presents with pharyngitis, fever, swollen cervical lymph glands and oedema of the soft tissues (‘bull neck’ appearance). The pseudomembrane can cause death due to respiratory obstruction.

Diphtheria, which affects the skin, appears as vesicles become ulcerated and covered with a hard, bluish-grey, raised membrane, usually on the limbs. Diphtheria toxin can also cause heart failure and paralysis by affecting the heart muscle, nervous and adrenal tissues. 

The best evidence to support the efficacy of diphtheria-containing vaccines is that the disease has been virtually eradicated in many countries since immunisation began. 

For example, there were no notifications for diphtheria in England and Wales in 2014, and no deaths. This compares with 61,000 cases of diphtheria in the UK in 1940, with 3,283 deaths. 

In the US, there were 206,000 cases of diphtheria in 1921 and 15,520 deaths. There were no cases of diphtheria in the US in the years 2004-2008. However, it is still prevalent in some countries, and death rates are highest in the under five age group, where 20% of those affected with diphtheria are likely to die. 

Haemophilus influenzae

Haemophilus influenzae can cause serious disease, especially in young children. 

The most common presentations of invasive disease are meningitis (60%), epiglottitis (15%) and bacteraemia without an obvious focus (10%). 

Before vaccination, it is estimated that in 2008 globally 203,000 children under five years died due to Hib (Haemophilus influenzae type b) . 

Hib is estimated to cause 2% of all cause-child mortality under five and 4% of non-neonatal mortality. There is now a national immunisation schedule in 68 countries worldwide. As a direct result of this, the all-cause pneumonia death estimates by WHO declined from 1.8 million in 2000 to 1.2 million in 2008.

Measles

Measles is an acute viral infection with features that include fatigue, common cold symptoms, conjunctivitis, cough, red spots in the mouth (Koplik spots), red rash and fever. Complications include ear infections, pneumonia, diarrhoea, seizures and, rarely, post infectious encephalitis (which occurs at around one week after the onset of the rash). Historical evidence shows that the measles vaccine is effective. As uptake of the vaccine has increased, the incidence of measles has fallen correspondingly. 

Before the measles vaccine was introduced in the UK in 1968, there were up to 800,000 each year with peaks every two years. When the combined measles, mumps and rubella (MMR) vaccine was introduced in 1988 and coverage exceeded 90%, notifications fell substantially. 

Meningococcal infection

Meningococcal infection commonly presents as meningitis or septicaemia, or both, and is caused by Neisseria meningitidis. 

Less commonly, meningococcal infection may present with pneumonia, myocarditis, endocarditis, pericarditis, arthritis, conjunctivitis, urethritis, pharyngitis or cervicitis.

The best evidence on the effectiveness of the meningococcal group C vaccine (MenC) is a huge fall in the number of cases of meningitis after the vaccine was introduced in the UK in 1999. Since this time, the incidence has decreased by 97%. Similar results have been seen in Canada and Australia. 

Pertussis

Pertussis (whooping cough) is a bacterial infection caused by Bordetella pertussis. Following an initial common cold-type stage, an irritating cough gradually becomes a paroxysmal cough, usually within one to two weeks. The paroxysms are often followed by the characteristic ‘whoop’. 

Severe complications and deaths are most common in babies less than six months of age. Possible complications include pneumonia or cerebral hypoxia resulting in brain damage. Repeated post-tussive vomiting may lead to weight loss.

Historical evidence has shown that the pertussis vaccine is effective. In 2008, about 82% of all infants worldwide received three doses of pertussis vaccine. The WHO estimates that, in 2008, global vaccination against pertussis averted about 687,000 deaths.

Pneumococcal disease

Pneumococcal disease can present as sinusitis, ear infection, pneumonia, bacteraemia or meningitis. It is a major cause of morbidity and mortality, especially in the very young, the elderly, and in people with a suppressed immune system. The pneumococcal vaccine can prevent about 50-70% of cases of pneumococcal infections.

Poliomyelitis

Poliomyelitis is a viral infection which attacks the nervous system. Early infection is often not apparent but symptoms can range in severity from a fever to meningitis or paralysis. Acute disease may present with fever, fatigue, headache and vomiting, often with stiffness of the neck and back (with or without paralysis). 

Historical evidence has shown the poliomyelitis vaccine to be effective. Today, the disease is on the verge of worldwide eradication, with only isolated cases still occurring in a few countries.

With the introduction of a vaccine worldwide, the number of cases has decreased dramatically. The WHO reports a reduction in the number of children affected by polio from 1,000 per day in 1988 to five per day in 2006. The WHO now lists many countries which have eliminated polio infection entirely. 

Rotavirus

Rotavirus infection causes a highly contagious gastroenteritis that usually lasts from three to eight days. People with rotavirus usually present with a fever, severe diarrhoea, vomiting and stomach cramps. Rotavirus infection can lead to dehydration. Most infections occur in children between one month and four years of age. 

By January 2015, rotavirus vaccination had been implemented in national vaccination programmes in 75 countries worldwide. As a direct result there has been a more than 90% reduction of rotavirus hospitalisations in these countries.

Smallpox

Smallpox was officially eradicated in 1980. This is testament to the success of an international collaboration across the world, which was in no small part due to immunisation. 

Tetanus

Tetanus is an acute infectious disease caused by tetanus toxin. Typical symptoms are muscle rigidity with painful contractions of the muscles. The muscle stiffness often involves the jaw (lockjaw) and neck, and then becomes more widespread.

Tetanus spores are present in soil and can be transmitted through any small wound. Therefore, tetanus can never be eradicated. 

The best evidence for the efficacy of the tetanus vaccine is the decline in the prevalence of the disease since immunisation was introduced. By the year 2000, 135 countries had eliminated neonatal tetanus and annual deaths from tetanus had dropped by 75% worldwide.

Other illnesses

Other illnesses which can prevented by immunisation worldwide include:  

• Cholera

• Hepatitis A and B

• Human papilloma virus

• Influenza

• Japanese encephalitis

• Mumps and rubella (as part of the MMR vaccine) 

• Rabies

• Tuberculosis

• Typhoid fever

• Yellow fever

• Varicella.

Advice for parents

Healthcare practitioners should discuss the following with parents of children who need immunisation:

• Explain the benefits of immunisation to parents, in particular emphasising that it helps prevent serious illness in children, especially potentially severe diseases such as meningitis and tetanus

• Explore any concerns that the parent may have, taking time to present the facts

• Reassure that vaccinations are safe. Pain, swelling and reddening at the site of injection are the most common side-effects, other effects are rare and usually only cause a mild fever

• Advise parents not to routinely give paracetamol or ibuprofen to prevent fever. However, if pain or fever is problematic after the child has been immunised then paracetamol or ibuprofen may be used.

How to administer vaccines in a child

• Obtain consent from a person with parental responsibility

• Ensure that there are no contraindications to the vaccine

• Ensure that the parent or carer has been fully informed about the immunisation 

• Discuss possible adverse reactions with the parent or carer and make them aware of how to treat them

• Check that the vaccine is correct, has been stored appropriately and has not expired.

When administering the immunisation:

• Wash the site with soap and water if it is visibly dirty

• Most vaccines are given by intramuscular (IM) injection (if the child has a bleeding disorder, use the subcutaneous (SC) route for vaccines normally given by the intramuscular route as this reduces the risk of bleeding). Do not give immunisations into the buttock

• Use a 25mm 23-gauge (blue) or 25-gauge (orange) needle for IM administration (a 16mm 25-gauge needle may be appropriate for pre-term or very small infants)

• Give IM and SC immunisations into the anterolateral aspect of the thigh. If an additional vaccine is required on the same day, use separate legs if possible, or inject at sites at least 2.5cm apart

• Rotavirus vaccine is given orally. To administer an oral vaccine, seat the child in a reclining position and administer the entire contents of the oral applicator into the child’s mouth (towards the inner cheek). If a baby spits out or regurgitates most of the vaccine, another single dose can be given (at the same visit)

• Record the date of administration, vaccine and product name, batch number, expiry date, dose administered, and site of administration for each vaccine.

If the child is anxious or nervous, several measures can be tried, including adopting a calm, sympathetic approach, giving patient explanations (to the child and the parent), preparing and administering the vaccine out of sight of the child, and using distraction techniques. 

Observe the child after vaccination to detect immediate adverse reactions. Ensure any bleeding has stopped and check the child has no symptoms of allergy before they leave.

Severe allergy (anaphylaxis) is extremely rare and usually becomes apparent within minutes. By the time the site has been checked for bleeding and documentation has been completed, most reactions will have become apparent.

Make a final assessment of the child before they leave the premises.

Bibliography

1. Andre FE et al Vaccination greatly reduces disease, disability, death and inequity worldwide Available from: http://www.who.int/bulletin/volumes/86/2/07-040089/en/
2. Ali A et al. Global practices of meningococcal vaccine use and impact on invasive disease Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4083163/
3. UNICEF and World Health Organisation. State of the world’s vaccines and immunization. Third Edition. Available from: http://www.unicef.org/immunization/files/SOWVI_full_report_english_LR1.pdf
4. World Health Organization Myths and Facts about vaccination Available from: http://www.who.int/features/qa/84/en/index.html