Immunisation facts, myths and misconception - an overview
Immunisation and the immune system
Myth: The body’s immune system can cope with infection without the help of vaccines. Fact: The immune system is a collection of specialised cells and chemicals that fight infection. Each time an infectious bacterium, fungus or virus (germ) is overcome, the immune system ‘remembers’ how to defeat that particular infection. If the immune system comes into contact with that particular infectious germ again, it can destroy it quickly, often before the person even notices any symptoms of illness. Without causing infection, vaccines trick the immune system into responding as if the body is under attack from a specific bacterium or virus by introducing:
dead or weakened versions of the germ
inactivated toxins from germs
molecules from the surface of the germ.
If the immune system encounters the live germ or toxin later, the immune system quickly recognises it and kills it.
Immunisation and the infant immune system
Myth: The immune systems of babies are protected through the placenta and breastfeeding, so they don’t need vaccination. Fact: Babies are exposed to many germs as part of the normal birthing process, including those from the vaginal canal, faeces and breast milk. Although their immune systems can meet these challenges, the immune system in an infant is still developing and needs to become active to protect against a range of bacteria and viruses. An infant will receive some natural protection against diseases transferred from the placenta, but the level of protection depends on the mother’s exposure to disease either by illness or vaccination. Breastmilk is also valuable for protection, but the protection is mainly for germs that infect the gut. The protection received from the placenta and breastmilk can be weak and only lasts for a few months.
Immunisation and immunity
Myth: Combining two or three vaccines into one injection may put a baby’s immune system under considerable strain. Vaccines should be separated and given at six-monthly or yearly intervals. Fact: Delaying vaccines would leave children vulnerable to catching diseases. Vaccines do not reduce a child’s immunity. Combining vaccines reduces the number of injections that babies and children need to receive. Vaccine preparations don’t cause infection, so an ‘all-out’ immune response is not triggered. In addition, the immune system is designed to handle multiple attacks, because in nature germs don’t attack the body one at a time. Each vaccine is carefully researched and produced so that it is suitable to be given at the earliest possible time to provide the best level of effectiveness and protection.
Immunisation and vaccine safety
Myth: Vaccines cause side effects and should be avoided. Fact: Vaccines provide a safe and efficient way to prevent the spread of many communicable diseases. Every vaccine used in Australia has been thoroughly tested for safety and effectiveness, approved for use by the Therapeutic Goods Administration (TGA) and is subject to ongoing monitoring and evaluation. However, vaccines are like any other medication and they may trigger side effects but these are mostly mild. This is why parents are generally advised to remain at the clinic for at least 15 minutes after their children are immunised. In the majority of cases, side effects are mild.
Immunisation and autism, diabetes and sudden unexpected death in infancy
Myth: Vaccinations can cause certain disorders, such as autism and diabetes, or contribute to the risk of sudden unexpected death in infancy (SUDI), which includes sudden infant death syndrome (SIDS) and fatal sleep accidents. Fact: These theories have been extensively investigated and dismissed. Immunisation reactions are generally mild and resolve by themselves without needing medical treatment. Reactions may include fever and soreness at the injection site. Serious immunisation reactions are exceptionally rare. Watch a video showing Telethon Kids autism researcher Professor Andrew Whitehouse talk about vaccination and autism.
Immunisation versus the risk of childhood diseases
Myth: Immunisation for childhood infectious disease is riskier than the disease. Fact: Childhood diseases such as measles and whooping cough (pertussis) are serious and potentially fatal. The risk of complications from disease is much higher than the risks of complications from immunisation. Parents who are fearful of autism, SUDI or other disease complications may choose not to have their children vaccinated. However, if vaccination levels in the community fall too low, disease epidemics can reappear. People with little first-hand experience of childhood infectious disease can underestimate the effects and complications of infectious diseases.
Some parents worry that the measles mumps rubella (MMR) vaccine can cause brain inflammation (encephalitis), but this risk for the vaccine is around one in one million. On the other hand, one in every 1,000 children who catch measles will experience encephalitis. Of these, one in 10 will die and four in 10 will have permanent brain damage.
Things to remember
Most research shows that some parents are concerned about vaccine safety and effectiveness.
Immunisation reactions are generally mild and resolve by themselves without needing medical treatment.
The risk of complications from childhood diseases is much higher than the risks from immunisation
