Childhood and Infant Immunizations

Toddler and infant immunizations (sometimes called vaccinations) are a means of protecting your child against infection.

Immunization has proved to be one of the most effective means of reducing death and disability as a result of serious infections. Some infections, like small pox, have been completely eradicated because of an effective worldwide immunization program.


This page gives an overview of immunizations in babies and toddlers. To go to a specific question, click on the link below or just keep reading for an overview.

What are Immunizations?

There are various types of vaccines used for childhood immunization. Each one is made to act against a particular virus or bacteria.

Vaccines act by stimulating the body to make defenses against the infection.

Some vaccines are referred to as live vaccines because the vaccine is the actual virus but without the part that makes you sick. Some vaccines use proteins that are similar to those in the bacteria or the virus and when they are given, the body builds up a protection against that protein which also means protection against the bacteria or virus.

To read about the diseases prevented by infant immunizations, click here.

To read about the how immunizations work, click here.

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Are childhood immunizations safe?

Toddler and infant immunizations are generally very safe. Before they are introduced, they have usually gone through extensive safety testing.

In general, most babies and toddlers do not have reactions to immunisations. If they do, the reactions are usually mild and of no long-term significance.

To read more about immunization side effects, click here.

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What is the point of immunizing my baby against diseases that are not common where I live?

Individual countries have their own immunization schedules based on the diseases that have caused problems in the past. If you don't see a disease very often, (say diphtheria, for example), it is because the childhood immunization program is so successful.

In the developed world, diseases like measles rarely cause any problems now because the immunization program has been in place for so long and the majority of the population is immunized and so there is hardly any virus around. When I worked in Ethiopia, where there was no routine childhood immunizations, measles would kill children. The mothers there would have walked days to get their children immunized because they know what a terrible disease measles can be.

If the majority of people stop immunizing their children, we could be in a situation like Ethiopia where measles becomes a killer disease again.

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I have am concerned about side effects from childhood immunizations

There has been a lot of negative publicity about toddler and infant immunizations - very little of this negative publicity is based on good research.

In the 1970's, there was a lot of negative publicity about the pertussis (whooping cough) vaccine and people were concerned the vaccine caused seizures and brain damage. We now realize that this was inaccurate and that the complications people were worried about, like seizures and brain damage, are much more likely as a result of getting the disease and not because you were given the vaccine. So being immunized is protective of these problems.

More recently, there has been controversy about MMR (measles, mumps, rubella vaccine) causing autism. There has been extensive research and population studies that show that MMR does not cause autism. To read more about autism and immunizations, click here.

To read more about infant immunization side effects, click here.

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Can my child have immunisations if he is allergic to eggs?

Children who are allergic to eggs can have all the usual childhood immunizations.

The only immunization that should be avoided if your child is allergic to egg is influenza vaccine.

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Should I delay immunizing my child if he is unwell?

If your child is acutely unwell with a fever of over 38 C (100.4 F), then the immunization should be postponed. If your child has a mild illness (say a runny nose) and doesn't have a fever, he can be immunized. Young children have so many viral infections (see Upper Respiratory Tract Infections), that to delay immunization for these would mean your child would not be protected from more serious infections.

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When should I start immunizations if my baby was born early?

Even if your baby is premature, the infant immunizations start at the baby's chronological age, not their gestational age. So if you have a premmie baby, say 32 weeks gestation (or 8 weeks early), the first immunizations are given at 6 - 8 weeks (depending on your country's immunization schedule) after the birth date, not the due date.

Premature babies need protection as much as babies born on time.

Premmie babies often require an extra booster dose of Hib (at 5 months of age). An exception to the timing of infant immunizations in premature babies is Hep B vaccine which is sometimes delayed until babies are at least 2 kg in weight if the mother is not a carrier.

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Are there any reasons my child can't be immunized?

Most children can be immunized. Reasons that prevent immunization include:

  • Children who have impaired immune systems cannot have some vaccines. Your doctor will know which ones. Luckily, if you live in an area where most of the children are immunized, you child will get some protection (called herd immunity) because the virus or bacteria won't be around.
  • An anaphylactic reaction to that particular vaccine in the past
  • If your child has had an anaphylactic reaction to egg, he cannot have the Influenza vaccine, but other vaccines like MMR are ok
  • A fever of more than 38 C (100.4 F) means the immunization needs to be delayed until your child is well
  • If your child has had a blood transfusion or blood products such as immunoglobulin, your child will have to wait at least 3 months and sometimes up to 11 months for MMR
  • If your child has had a live vaccine, such as BCG, your child will need to wait at least 4 weeks before having another live vaccine like MMR

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Is it safe to have so many shots?

Multiple vaccines do not weaken the immune system. Many parents are concerned that there seem to be more and more childhood immunizations. They are concerned that it is too much for their young child's system.

In actual fact, although we can now prevent many more diseases with immunizations, the actual load of antigen (foreign body) that is presented to your child's immune system now, with the 21st century childhood and infant immunization schedule, is considerably less than the antigen load presented in the past. For example, in the 1980's there were less vaccines given but the antigen load was over 3000. With the 2000 childhood immunizations there were more vaccines but the antigen load was less than 130.

With the newer childhood and infant immunizations, it has been estimated that if 11 vaccines were given at one time (which is actually more than are given at one time), it would only "use up" about 0.1% of the child's immune system. So you don't need to be concerned about damage to your child's immune system from the number of vaccines (shots) your child receives.

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What are Recommended Childhood Immunizations?

Each country has its own recommendations for toddler and infant immunizations based on the diseases that are most problematic. Some immunizations, like tetanus, diphtheria, whooping cough, measles, mumps, rubella and Hib (Haemophilus influenzae type B) are universal.

Links to different country schedules for toddler and infant immunizations are given below:

  • To read about the United States immunization schedule, click here
  • To read about the Canadian immunization schedule, click here
  • To read about the Australian immunisation schedule, click here
  • To read about the New Zealand immunisation schedule, click here
  • To read about the British immunisation schedule, click here
  • To read about the South African immunisation schedule, click here
  • To read about the Indian immunisation schedule, click here

To read about the diseases prevented by the immunization schedule, click here.

To read about the how immunizations work, click here.

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What General Measures Help Prevent Infection?

As well as providing infant immunizations for you child, you should also follow the general measures below:

Remember to:

  • cover your nose and mouth when sneezing or coughing
  • discard of all used paper tissues
  • wash your hands frequently, especially when unwell

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Search This Site


Useful Websites


  • Lissauer T, Clayden G. Illustrated Textbook of Paediatrics. Mosby 2007. ISBN 978-0-7234-3397-2
  • Offit et al. Addressing Parents' Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant's Immune System? Pediatrics Jan 2002.109:124-129

To go to the top of the Toddler and Infant Immunizations page, click here

To read more about infant immunization side effects, click here.

To read about the diseases prevented by immunizations, click here.

To read about how immunizations work, click here.

To go to the Infections page, click here

To return to the Home page, click here

Last reviewed 17 August 2010

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Dr Maud MD

Dr Maud MD (MBChB, FRACP, FRCPCH), a specialist pediatrician, provides health information and medical advice for parents of babies and toddlers. Read more about Dr Maud.

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