How do vaccines work?
Harmful micro-organisms will reproduce quickly inside the body where they have food, warmth and moisture to thrive. They cause disease symptoms when they damage cells or make poisons (antigens) that damage cells. This is called an infection. The body tries to stop invading ‘microbes’ by its barriers to infection such as the skin which repairs itself when wounded to stop foreign bodies from getting in. Sweat is produced from the skin’s pores and this contains chemicals to reduce the growth of micro-organisms. We even have an enzyme in our tears called ‘lysozyme’ which kills off bacteria. The hydrochloric acid in our stomach kills off many of the micro-organisms entering our body by food and drink.
Despite these defences dangerous micro-organisms can still manage to infect us if we come into contact with them. The role of our immune system is to fight off invading microbes. Our white blood cells will detect foreign bodies and produce antibodies to kill them in order to prevent them damaging cells and spreading in the body. Micro-organisms that cause disease are called ‘pathogens’ and once they get inside us and start to reproduce they cause infection. Some diseases can kill or cause lasting damage so vaccines are given to prepare your child’s immune system to fight them off if they come into contact with them. Vaccines contain a small part of the bacterium or virus that causes the disease, but the injected micro-organisms are dead or inactive. White blood cells make antibodies to digest the microbes. The antibodies then remain in the blood system to protect your child should they come into contact with the disease again. Because vaccines have been used so successfully in the UK, diseases such as tuberculosis, diphtheria, tetanus and whooping cough have almost disappeared from this country.
Why is it important to keep vaccinating?
Even if there are only a few cases of the disease if we took away the protection given by vaccination more and more people will be infected and the disease will transmit to others. Soon we would undo the progress we have made over the years. This is why we need to carry on vaccinating as many people as possible until the disease is virtually eradicated just like smallpox was in 1980.
Getting your child vaccinated will bring us one step closer to eradicating Polio, which caused as many as 8000 cases in the UK in epidemic years before a vaccine was introduced to prevent it.
What is polio?
Polio is a virus that attacks the nervous system which can cause permanent paralysis of muscles. If it attacks the chest muscles or the brain, polio can kill. Because of the success of the polio vaccine there have been no cases of natural polio infection in the UK for over 20 years.
The Three different symptom phases:
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A mild form called abortive polio (most people with this form of polio may not even suspect they have it because their sickness is limited to mild flu-like symptoms such as mild upper respiratory infection, diarrhoea, fever, sore throat, and a general feeling of being ill)
- A more serious form associated with aseptic meningitis called non-paralytic polio (1% to 5% show neurological symptoms such as sensitivity to light and neck stiffness)
- A severe, debilitating form called paralytic polio (this occurs in 0.1% to 2% of cases)
The long term effects of Polio:
An estimated 80% of people living in the UK who have had polio, (around 40,000) are now being affected by the long term effects of polio. Their symptoms include extreme fatigue, muscle and joint pain, lack of strength and stamina, breathing and swallowing difficulties, mood changes, and sleep problems.
The Benefits of Vaccination
It is important to vaccinate a large proportion of the population in order to prevent an epidemic of a disease. It speaks for itself that the fewer the number of people who aren’t vaccinated the less chance the disease has of spreading. The health service in this country aims to vaccinate approximately 95% of the population to achieve what is called ‘herd immunity’.
In the long term we will be a healthier nation. Fewer individuals will suffer from long term illness and disability from contracting more serious diseases. The burden on the National Health Service will be vastly reduced from sick children and adults.
What are the Risks
Vaccination can never be completely safe for everyone because each person will have a different reaction. For most people it will be completely safe and there will be no side effects at all. We must remember to balance this against the benefits when we are making a choice about whether to have a vaccination or not.
Very rarely, some children can have an anaphylactic reaction within a few minutes of having a vaccine. This can cause breathing difficulties and sometimes collapse. This is a severe allergic reaction that can occur in one in a million immunisations and needs urgent treatment. A child should recover with immediate treatment.
Children who have any condition that affects the immune system such as cancer, a transplant or immunodeficiency should not be vaccinated. If your child has a fever then the immunisation should be put off until the child is well.
Most commonly children who have just been vaccinated can experience some redness, swelling or tenderness where they had the injection. This can be a little sore but usually disappears by itself within a few days. They may also feel unwell, irritable or have a temperature (fever). This can be treated with paracetamol and plenty to drink.
In this country you have the right to choose whether your child is vaccinated. Although vaccination can never be completely safe for everyone it is considered to be the safest way to protect your child from very serious diseases. Remember that epidemics can only be prevented where a large percentage of the population are vaccinated.
By William Roberts
