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Why is the schedule the way it is?

Key facts

  • The vaccination schedule is carefully planned so that babies and children get the best possible protection against serious infectious diseases as soon as they can.

  • It is important that children get all their vaccinations on time to ensure they have the best possible protection against infectious diseases. 

  • If vaccination is delayed or spaced out, children are left without protection for longer than they need to be. 

Last updated on 30 April 2023.
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The schedule is carefully planned to protect babies and children as soon as it is possible.

Some vaccines don’t work if babies get them too young, so we give those vaccines to babies when they’re older. The measles vaccination is one of these.

Some diseases are much more serious when very young babies get them, so we recommend vaccinating against them when babies are very young. Pertussis (also known as whooping cough) is one of these.

It takes many years of careful research by independent experts to work out the right time to give each vaccine so that they get the best possible protection against serious infectious diseases as soon as they can.

Why do children get so many vaccines in the first two years?

Children get as many vaccines as possible in the first two years so they can be protected as soon as possible from diseases that can be serious.

It takes many years of research to work out the right time to give each vaccine. Independent experts gather information to help them make their recommendations. They consider which diseases Australian children are most likely to be exposed to; how serious those diseases can be for children at different ages: which vaccines are safest and which work best; how many doses are needed to provide full protection; and the age when the vaccines will give the best protection.

What happens if I delay or leave out certain vaccines?

When vaccination is delayed or spaced out, children are left without protection from diseases for longer than they need to be. That’s why we recommend vaccinating children on time – so they can be protected as soon as possible.

Children and babies are often more likely to catch infectious diseases when they are young, and more likely to get seriously ill when they do catch them. The National Immunisation Program (NIP) Schedule has been designed to protect children when they need it most.

If you choose to space out the vaccines, it means your child will need to have more vaccination appointments. Researchers have found that visiting the doctor for one needle is just as stressful for children as visiting the doctor for two needles at once.1

Are the diseases still around anyway?

Some of the diseases children are vaccinated against, like whooping cough and flu, are still common among children living in Australia.

Others, like measles, are less common in Australia but are more common in nearby countries in the Pacific and South East Asia. Vaccinating your child will protect them from diseases which could be brought into Australia by travellers, or which they might catch if they travel overseas with you.

Some of the diseases we vaccinate children against, like polio, have become very rare in Australia because vaccination has stopped them from spreading. We still vaccinate Australian children against these diseases to stop them from coming back.

Why has the schedule changed since I had my last baby?

The schedule of recommended vaccinations changes from time to time for a number of reasons. For example:

  • A new vaccine could be added to the schedule, protecting children from a disease it hasn’t been possible to protect them from before.
  • A ‘combination vaccine’ that provides protection against multiple diseases might be released after years of research and development, reducing the number of needles children need to get overall.
  • A vaccine that is better, safer, more effective or less expensive than previous versions might be introduced.

Sometimes booster doses are added to the schedule to strengthen the protective effect of a vaccine.

Why is the schedule different in other countries?

The schedule is different in other countries because patterns of disease, strains of viruses or bacteria, medical care, available vaccines and their costs vary from country to country.

Medical experts and health economists consider all the available information about children and diseases and decide which vaccines should be given to children in their countries at what ages. In Australia, medical experts and health economists from a variety of independent advisory groups decide which vaccines should be provided to children living in Australia.2