immunisation and vaccines

immunisation and vaccines

Researching vaccinations often unturns a wealth of conflicting information. Here are the answers to common questions regarding vaccinations and your baby.

Vaccines - what's in them?

Depending on the disease, the materials making up a vaccine may vary. They may contain:

  • A very small dose of a live, but weakened form of the virus
  • A very small dose of killed bacteria or small parts of bacteria
  • A small dose of a modified toxin produced by bacteria
  • A small amount of a preservative or an antibiotic to preserve the vaccine
  • A small amount of an aluminium salt for a better immune response

How long does it take for a vaccination to become effective?

The immune system usually responds to a vaccination a couple of weeks after application, and is most effective when several doses are administered, as most immunisations require. For example, a child who has only received two out of the three DTP (diphtheria, tetanus, pertussis) vaccine is only partly immunised. Any exposure to these diseases could result in the child becoming ill as her immune system would not be strong enough to combat the diseases.

How long does the immunisation protection cover?

Some immunisations are designed for a lifetime span but most require a booster dose. The booster dose increases the initial vaccination as time goes on and the effect weakens. Tetanus can last up to 30 years before a booster is needed, whilst the whooping cough would need to be boosted after only five years.

Does the immunisation offer full protection against the disease?
Immunisation does not protect 100% of all immunised patients due to a possible failure rate with every vaccination, and the need for booster doses to update immunity.

Below are some general failure rates:

  • 15% of children immunised against whooping cough will not be protected - although should they get the disease, their symptoms will be less severe.

Why are children the dominant recipients for immunisations?
Childhood is the most vulnerable age for serious infections and the common likelihood of childhood diseases - measles, mumps, whooping cough and rubella. A child's immune system is not yet developed like an adult's and needs help to fight against infection. Even though a transfer of antibodies through the placenta at birth and continued through breastfeeding, these antibodies eventually wear off after a couple of months to leave your child protected.

Are there any side effects to immunisation?

The most common side effects of immunisation are redness and soreness at the site of the injection followed by a mild fever. These side effects are generally minor, temporary (lasting 1 - 2 days) and can be controlled with paracetamol. Serious side effects are very rare but if they do occur consult your GP.

A reaction to the MMR vaccine may occur 5-12 days after immunisation and will last for 48 hours, but will not make your child infectious. Symptoms include; mild fever, faint rash, head cold, runny nose, cough and/or puffy eyes because of the measles part of the vaccine, swelling of neck glands three weeks after injection because of the mumps part of the vaccine.

Important - please read!



Australian Childhood Immunisation Register
Check the current vaccination schedule here.

Read our articles on the Immunisation schedule and Immunisation Register.

Discuss vaccinating your baby or toddler in the Essential Baby health forums.