Vaccinations – common questions answered

When it comes to immunisations, there’s an abundance of discussion and often heated debate that takes place surrounding the issue.

Yet, due to the intense passion the subject evokes, seldom does the conversation involve any real facts about vaccination.

In fact, more often than not, discussion about immunisation quickly deteriorates into a slanging match, rather than the exchange of helpful information many parents are seeking.

As a result, parents who are looking for real data about vaccinations for their children can be left confused, which is a serious concern when you consider recent declines in immunisation rates.

To clear up some of the confusion, we asked the neonatologist Dr Howard Chilton to answer some of the most frequently asked questions about immunisation.

How do immunisations work?

The aim of immunisation is to protect the body from viral and bacterial organisms (germs) and the poisons (toxins) they produce when they enter the body.

This is achieved by giving the body a tiny dose of killed or altered germ, or inactivated toxin (toxoid).

This tiny dose of the germ makes the body produce an antibody (that is, a neutralising agent) that fights infection by that germ.

By teaching the body to produce the appropriate antibody in advance of invasion by the germ, we can get it to develop a solid defence against the disease those germs produce.

The germ never gets started. As they enter the body these germs are overwhelmed and removed by our defence mechanisms.

Why are vaccinations so important?

There is an overwhelming and vast body of scientifically validated evidence that shows that immunisation works, and provides major health benefits to individuals and communities.

The risks are vanishingly small both to the individual, and in comparison to the risk posed by the infectious diseases themselves.

Are vaccinations free in Australia?

All vaccines listed in the following National Immunisation Program (NIP) schedule are free, based on your eligibility for Medicare benefits.

Which diseases are covered via the recommended immunisation schedule and at what ages are they required?

To get the best possible protection, make sure your child has their immunisations on time, every time.


Hepatitis B (usually offered in hospital)


Can be given from 6 weeks of age. First dose of DTPa (triple antigen that protects against diphtheria, tetanus and pertussis/whooping cough), Hepatitis B, Hib vaccine (influenza type B), Salk (polio) vaccine, Pneumococcal vaccine, and Rotavirus.


Second dose of DTPa (triple antigen that protects against diphtheria, tetanus, and pertussis/whooping cough), Hepatitis B, Hib vaccine, Salk (polio) vaccine, Pneumococcal vaccine, and Rotavirus.


Third dose of DTPa (triple antigen), Hepatitis B, Salk (polio) vaccine and Pneumococcal vaccine.

Additional vaccines for Aboriginal and Torres Strait Islander children and medically at-risk children (QLD, NT, WA, and SA): Hepatitis A.


Meningococcal ACWY, Measles, mumps and rubella vaccine (MMR), Pneumococcal.


Haemophilus influenzae type B (Hib), measles, mumps, rubella, Chicken pox (varicella), Diphtheria, tetanus, pertussis (whooping cough).

Additional vaccines for Aboriginal and Torres Strait Islander children (QLD, NT, WA, and SA): Hepatitis A.


Pre-school booster: DTPa (triple antigen) and Salk (polio) vaccine.

Additional vaccines for medically at-risk children: Pneumococcal

Which vaccinations are recommended for pregnant women?

Pertussis (whooping cough) and Influenza

What about the flu vaccine for babies?

If your child is between 6 months and 5 years of age, you’re eligible to receive a free flu shot each year. The same applies if you’re pregnant during any trimester.

Are vaccinations safe and what are the side effects?

They are very safe indeed.

Fewer than 20% of babies will get a minor side effect such as mild fever or sore injection site.

Vaccines are unique in medical treatments in that they are given for prevention of disease to all healthy babies.

Because of that, the medical establishment is deeply aware of its responsibilities to make it very safe.

This is a primary medical ethic ‘first, do no harm’.

The present schedule of immunisations are constantly being reviewed to be certain that they are the best and safest, and there is very active surveillance for side-effects that is ongoing, constant, and very detailed.

Can immunisation cause disease?


Do vaccines overwhelm baby’s immune system?

The amount of killed or altered germs given to a baby is incredibly tiny in comparison to the amount of germ received when one is infected.

Why do some immunised children still get the disease they were immunised against?

Not everybody generates an adequate antibody level in their blood in response to a vaccine.

For instance the whooping cough vaccine still leaves about 10% for recipients vulnerable, though if they catch the disease they will get a much less severe form.

Can babies and children still be immunised if they are sick?

It is true that it is not recommended to immunise children when they are sick.

The reason is not that the immunisation will be less effective but if the child gets more unwell from the original illness that the vaccine will be inappropriately blamed.

Is it too late to immunise a child who has missed one or more vaccinations?

No. Comprehensive catch-up programmes are available for all ages. It’s never too late to immunise!

Does the MMR vaccine cause autism and how have such rumours developed?

There is no relationship between MMR vaccine and the cause of autism.

A few years ago there was a major splash in the media, especially in the UK, about this vaccine possibly being related to autism.

This caused a very careful and thorough re-examination of all the information by experts from around the world.

All the panels agree that there is no relationship, other than coincidence.

The tiny fragment of scientific data that seemed to point to this has been shown conclusively to be wrong, even fraudulent.

Even the journal in which it appeared apologised to the readership for publishing it and misleading them.

Why is there so much misinformation circulating about vaccinations?

Over the years I have met a lot of people who don’t ‘believe’ in immunisation.

They are often intelligent, caring people who may have had a personal connection with a bad vaccination experience.

Alternatively they may have a general bias against conventional medicine.

Either way, they have ended up doing their own Internet research on the subject.

Unfortunately the Internet has no filter for the information presented, so it is impossible for them to know what is truly scientifically valid and what is biased half-truth, or wild speculation.

It is also easy to ‘cherry pick’ bits of information from genuine scientific papers and come to completely erroneous conclusions.

One argument used is that in the West, infectious diseases were generally on the wane before the introduction of immunisation. This was because of improvements in hygiene, sanitation and nutrition.

This is certainly true insofar as this improved death rates, but it had little effect on infection rates.

Subsequent immunisation programmes had a clear and separate impact, independent of these environmental improvements to improve the incidence of the diseases occurring.

That was how smallpox was finally eradicated in 1977.

What are the overall benefits of immunisation to the individual child and to society?

There is an overwhelming and vast body of scientifically validated evidence that shows that immunisation works, and provides major health benefits to individuals and communities.

They lower the incidence of the targeted infectious diseases to a minimal level, sometimes eliminating them completely.

They consequently prevent numerous hospital admissions, further illness and even death from the complications of these diseases.

Quite apart from the decrease in sickness and deaths, this also means our health tax dollars can be spent on more efficient and effective ways of improving the health of our community.

They also prevent the infections being passed on to those members of our community who are too young (such as babies before the age they can be vaccinated) or too sick or those whose immunity has been compromised (such as some cancer patients under treatment).

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