What is immunization?

Immunization protects children (and adults) against harmful infections before they come into contact with them in the community.

Immunization uses the body’s natural defence mechanism – the immune response – to build resistance to specific infections. Nine diseases can be prevented by routine childhood immunization – diphtheria, tetanus, whooping cough, poliomyelitis (polio), measles, mumps, rubella, Haemophilus influenza type b (Hib) and hepatitis B. All of these diseases can cause serious complications and sometimes death.
Immunization is given as an injection or, in the case of the polio vaccine, taken as drops by mouth. Immunization helps children stay healthy by preventing serious infections.

Immunization and vaccination

Technically ‘vaccination’ is the term used for giving a vaccine – that is, actually getting the injection or swallowing the drops. ‘Immunization’s the term used for the process of both getting the vaccine and becoming immune to the disease as a result of the vaccine. Most people use the terms ‘vaccination’ and ‘immunization ’interchangeably but their meanings are not exactly the same because immunity follows vaccination in most, but not all, cases.

How does immunization work?

All forms of immunization work in the same way. When someone is injected with, or swallows, a vaccine, their body produces an immune response in the same way it would following exposure to a disease but without the person getting the disease. If the person comes in contact with the disease in the future, the body is able to make an immune response fast enough to prevent the person from getting sick.

What does a vaccine contain?

Some vaccines contain a very small dose of a live, but weakened form of a virus. Some vaccines contain a very small dose of killed bacteria or small parts of bacteria, and other vaccines contain a small dose of a modified toxin produced by bacteria. Vaccines may also contain either a small amount of preservative or a small amount of an antibiotic to preserve the vaccine. Some vaccines may also contain a small amount of aluminium salt which helps produce a better immune response.

How long do immunizations take to work?

In general, the normal immune response takes several weeks to work. This means protection from an infection will not occur immediately after immunization. Most immunizations need to be given several times to build long-lasting protection. A child who has been given only one or two doses of the diphtheria-tetanus-pertussis vaccine (DTP a) is only partially protected against diphtheria, pertussis (whooping cough) and tetanus, and may become sick if exposed to these diseases. How long do immunizations last? The protective effect of immunizations is not always life-long. Some, like the tetanus vaccine, can last up to 30 years, after this time a booster dose may be given. Some immunizations, such as whooping cough, give protection for about five years after a full course.

Is everyone protected from disease by immunization?

Even when all the doses of a vaccine have been given, not everyone is protected against the disease. Measles, mumps, rubella, tetanus, polio and Hib vaccines protect more than 95% of children who have completed the course. Three doses of the whooping cough vaccine protect about 85% of children who have been immunized and will reduce the severity of the disease in the other 15% of children (who have also been immunized) if they do catch whooping cough. Booster doses are needed because immunity decreases over time. Three doses of the hepatitis B vaccine protect over 95% of children.

Why do children get so many immunizations?

A number of immunizations are required in the first few years of a child’s life to protect the child against the most serious infections of childhood. The immune system in young children does not work as well as the immune system in older children and adults, because it is still immature. Therefore more doses of the vaccine are needed. In the first months of life, a baby is protected from most infections by antibodies from her or his mother which are transferred to the baby during pregnancy. When these antibodies wear off, the baby is at risk of serious infections and so the first immunizations are given before these antibodies have gone.

What are the side effects of immunization?

Common side effects of immunization are redness and soreness at the site of injections and mild fever. While these symptoms may concern you and upset your child at the time, the benefit of immunization is protection from the disease. Paracetamol might be required to help ease the fever and soreness. For more information, refer to the Common side effects of immunization and what to do about them. Other side effects are very rare but if they do occur, a doctor should be consulted immediately.

Frequently asked questions:

Why is it important for children to be vaccinated?
Children need to be vaccinated in order to protect themselves from certain infectious diseases.

Why should all children be vaccinated?
Vaccinations prevent the spread of disease within the community.

Where do I go to have my child vaccinated?
Your local clinics and community health centres in South Africa will provide free vaccinations for your child.

When should my child be vaccinated?
At birth, 6 weeks, 10 weeks, 14 Weeks, 9 months, 18 months, 6 years and at 12 years old.

Does my child need to have all the vaccinations?
Yes, your child must have all the vaccinations on the attached schedule.

Which diseases will the vaccinations protect my child from?
Tuberculosis, Polio, Rotavirus Gastroenteritis, Diphtheria, Tetanus, Whooping cough,
Haemophilus Influenza -type B, Hepatitis B, Pneumococcal Infection, and Measles are the vaccinations that your child will be protected against.

DID YOU KNOW:

Pneumonia kills more children around the world than any other illness. Many caregivers, however, do not know the key symptoms – fast and difficult breathing – that indicate when a child needs immediate treatment

WHICH DISEASES DO CHILDREN GET VACCINATED AGAINST?

POLIO

1. Polio is caused by germs (polioviruses), which attack nerves, causing weakness or paralysis of the leg and/or arm and if severe, may involve respiratory or breathing muscles.

The virus can cause permanent muscle weakness, paralysis and sometimes death. In the majority of people, there are no symptoms. Of the infected people with symptoms, most will have mild symptoms including headache, fever, sore throat and vomiting.

MEASLES

Measles is a highly contagious viral infection that causes a high fever and a rash and can lead to diarrhoea and dehydration, deafness, eye complications, pneumonia, brain damage and even death.

An infected child develops a runny nose, fever, hacking cough and red eyes. Tiny white spots appear on the inside of the mouth followed by a sore throat. A mildly itchy rash appears 3-5 days after the start of symptoms. Starting around the ears and spreading to the trunk, arms and legs, the rash starts off as flat red areas that soon become raised. The child may develop a very high temperature of 40 ºC.

Haemophilus Influenza Type B (Hib)

Haemophilus Influenza Type B (Hib) is a serious illness that affects mainly children under the age of five years. Hib causes infection in the respiratory tract, which can spread to other organs.

It spreads through the bloodstream and infects the joints, bones, lungs, skin, face, neck, eyes, urinary tract and other organs. The bacteria may cause two severe, often fatal infections: meningitis and epiglottitis. Death from Hib disease is common in children under the age of one.

HEPATITIS

 Hepatitis B is an infection of the liver, which can cause liver damage, liver cancer and death. Hepatitis B is also spread through contact with saliva, tears, breast milk, urine, vaginal fluid and semen.

A pregnant woman infected with hepatitis B can transmit the virus to her baby during birth.

WHOOPING COUGH

 Pertussis (whooping cough) is a highly contagious infection caused by the bacteria Bordetella pertussis, which results in coughing that usually ends in a pro-longed high pitched, deeply in-drawn breath ( the whoop).

It starts with a headache, fever and cough. The strenuous coughing bouts make it hard for a child to eat, drink or even breathe. The duration of the disease is a minimum of 6 weeks.

TETANUS

Tetanus (lockjaw) occurs when a toxin produced by a tetanus germ from the soil enters a cut or wound.

The germ can cause muscle spasms, breathing and heart problems, and death. The chances of dying from this condition are very high.

DIPHTHERIA

Diphtheria is a dangerous bacterial disease of the upper respiratory tract, which makes it difficult to breathe.

Children who survive diphtheria disease suffer permanent damage such as blindness, deafness and brain damage.

TUBERCULOSIS

Tuberculosis (TB) Meningitis is a serious disease that can affect people of all ages.

Those that get TB suffer from coughing for a long period of time, chest pain, sweating at night, weight loss and even death if left untreated.

In young children, the TB germ may infect the brain and cause meningitis, or it could also enter the blood and spread to other parts of the body. TB can kill young people. The best protection for young children for diseases caused by TB germ is the BCG vaccine.

ROTAVIRUS

Rotavirus Gastroenteritis is one of the most common causes of diarrhoea in children and spreads quickly and easily.

The rotavirus affects nearly every child before their 5th birthday. Diarrhoea from rotavirus can quickly lead to dehydration. Dehydration can result in hospitalisation and even death for children who do not receive treatment in time.

Symptoms begin with fever and vomiting, followed by watery diarrhoea, which typically lasts 5-7 days. The child becomes weak and listless from fluid loss. In South Africa, 6 children die per day from the rotavirus.

The vaccination to prevent the rotavirus is now available to children between 6 weeks – 24 months of age at your local clinic.