Immunisation

Why vaccinate your child?

As a parent, you may not like seeing your baby or child being given an injection. However, vaccination is an important step in protecting your child against a range of serious and potentially fatal diseases.
 
Vaccinations are quick, safe and extremely effective. Once your child has been vaccinated against a disease, their body can fight it more effectively. If a child isn’t vaccinated, they will have an increased risk of catching the illness.
 
There will always be some children who are unavoidably unprotected because:
 
  • they can’t be vaccinated for medical reasons
  • they’re too young to be vaccinated
  • they can’t get to the vaccine services
  • the vaccine doesn’t work (although this is rare)
 
However, if more parents have their children vaccinated, then more children in the community will be protected against an illness. This lowers the chance of an disease outbreak.
 
The only time that it’s safe to stop vaccinating children against an illness is when the disease has been wiped out worldwide.
 
For example, when every country had eliminated smallpox in 1979, vaccination against the disease was stopped. It’s hoped that polio will soon be eradicated and that measles will follow.

Can you overload a child’s immune system?

You may be concerned that too many vaccines at a young age could “overload” your child’s immune system, but this really isn’t the case. Studies have shown that vaccines don’t weaken a child’s immune system.
 
As soon as a baby is born, they come into contact with a huge number of different bacteria and viruses every day, and their immune system copes well.
 
The bacteria and viruses used in vaccines are weakened or killed, and there are far fewer of them than the natural bugs that babies and children come into contact with. In fact, if a child was given 11 vaccines all at the same time, it would only use a thousandth of their immune system!

How vaccines work

Vaccines work by stimulating our immune system to produce antibodies (substances produced by the body to fight disease) without actually infecting us with the disease.
 
They trigger the immune system to produce its own antibodies, as though the body has been infected with a disease. This is called “active immunity”. If the vaccinated person then comes into contact with the disease itself, their immune system will recognise it and immediately produce the antibodies they need to fight it.
 
Newborn babies are already protected against several diseases, such as measles, mumps and rubella, because antibodies have passed into them from their mothers via the placenta. This is called “passive immunity”. Passive immunity only lasts for a few weeks or months.
 
In the case of measles, mumps and rubella, it may last up to one year (which is why the MMR jab is given to children just after their first birthday).

How are vaccines made?

The first step is to make the organism (called the pathogen) that produces the disease. The pathogen is a virus or a bacterium. Viruses and bacteria can be mass produced in the laboratory by infecting cells grown in tissue culture.
 
The pathogen must then be altered to ensure that it doesn’t trigger the disease itself. This can be done by:
 
  • weakening, or “attenuating”, it by growing it repeatedly to select a strain that’s less dangerous – MMR vaccines are attenuated
  • taking out the part of the pathogen that causes the immune response and using this in the vaccine – the Hib vaccine is made in this way
  • using the toxin that the pathogen makes and inactivating it – this is how the tetanus vaccine is produced
 
The treated pathogen is then combined with other ingredients, such as stabilisers and preservatives, to produce a vaccine dose.