Mamamia Team Thursday 16 August 2012 1:17pm

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Vaccination

There have been more than 40 reported cases of measles in Sydney’s south west this week with 10 affected people being taken to hospital.

A spokesperson for the South Western Sydney Public Health Unit has warned that all of those who have been hospitalised were not fully immunised against the disease.

The Herald Sun reports:

The majority of those affected have been school-aged children and babies under 12 months old. The Department of Education confirmed four high schools and a number of primary schools had circulated letters of warning to parents…

Meanwhile, Australian Doctor magazine has revealed the number of parental objections to vaccinations are at an all-time high. According to statistics collected from the Australian Childhood Immunisation Register, 30,882 parents have formally objected to their child being immunised.

Of the more than two million children on the register, more than 6000 have no vaccination history.

The risks of failing to immunise children against potentially deadly diseases has been well documented on Mamamia (here and here). But with the anti-vaccination movement apparently gaining ground, we thought it was about time we revisited Dr Rachael Dunlop’s post about the common myths about vaccination and why they’re wrong.

Please read it and share this post among your social network so we can work against the dangerous misinformation circulated by the (Anti) Australian Vaccination Network (AVN):

Myth 1: Vaccines cause autism.

No doubt you’ve heard this myth – it’s been around for some time now. In a nutshell, there is no solid scientific evidence for a link between vaccines and autism. And believe me, science has been looking for well over 14 years. The theory that vaccines cause autism was first suggested by Andrew Wakefield in 1998. Since then, Wakefield’s paper has been discredited and withdrawn from The Lancet and Wakefield has lost his medical licence for showing “callous disregard” for children’s welfare.

Since 1998 there have been countless large and comprehensive studies looking for a link between vaccines and autism, but the evidence keeps coming up negative. The largest study was done in Denmark and covered all children born from January 1991 through December 1998. A total of 537,303 children of which eighty-two percent were vaccinated for MMR were examined and there was no association between vaccination and the development of autistic disorder.

Further, in August 2011, an exhaustive review of the scientific literature by the Institute of Medicine in the US concluded that overall “few health problems are caused by or clearly associated with vaccines”. And when I say “exhaustive review”, I mean 12,000 peer-reviewed articles, covering eight different vaccines were pored over by a committee of 18 experts in the largest review of adverse events associated with vaccines since 1994. It was a thorough and herculean effort concluding that there is no causal relationship between vaccines and autism.

Myth 2: Vaccines contain mercury

Mercury was removed from all routine childhood vaccines in Australia in the year 2000 (with the exception of one type of HepB vaccine which contains trace amounts) and it was never in the MMR vaccine. Prior to 2000, thimerosal, an organomercury compound, was used in the manufacturing process of vaccines as a preservative. The process left only trace amounts in the finished product – you ingest more mercury when you eat a can of tuna than you would ever get from a vaccine. Also there are two types of mercury – methyl mercury is the scary environmental toxin that “bioaccumulates” in your body, and ethyl mercury the type found in thimerosal, which does not bioaccumulate.
If thimerosal was implicated in autism, you would expect a significant drop in cases after its removal. Instead the opposite is true – autism rates continue to rise.

Myth 3: Vaccines contain toxic ingredients

For example, some viruses are grown on cell lines in the laboratory that were obtained from aborted fetal tissue many years ago. When a virus is grown on cells like these, it is extensively purified and many steps later, prepared into a vaccine. To say there are aborted human fetus cells in the vaccine is a bit like saying there is dirt in apples since they were once grown on a tree that grew in dirt. It’s misleading, scaremongering and simply not true. As for formaldehyde, there are trace amounts of formaldehyde in vaccines but much less than what your body naturally produces everyday.

Some vaccines do contain tiny amounts of metals like aluminium which have been used for over 80 years to increase the effectiveness of the vaccine. These are known as “adjuvants” and work like a booster to kick start the immune system into making antibodies. But just as the “dose makes the poison”, the concentrations of these metals are so low as to not be harmful to the body. Similarly, small doses of paracetamol cure pain but large doses have been known to cause liver failure.

Myth 4: Vaccines have never been tested.

All vaccines currently available in Australia must pass stringent safety testing before being approved for use by the Therapeutic Goods Administration (TGA), which is our government body responsible for regulating pharmaceuticals. Multiple clinical trials for safety and effectiveness are also performed as part of the development process (which takes anywhere between 10 to 15 years, and many millions of dollars) and safety monitoring continues for as long as the vaccine is in use.

For example with the polio vaccine, two million kids were involved in the field trial which was conducted in the US in 1954. More recently, the safety of the new cervical cancer vaccines was studied in large-scale clinical trials involving more than 50,000 people before being licensed for use. Safety continues to be monitored after 35 million doses with the majority of side effects being fever, headache and other minor ailments.

Like any medical procedure there are risks associated with the use of vaccines. This was brought to light in 2010 when dozens of kids suffered high temperatures and convulsions following administration of the flu vaccine. The vaccine was immediately withdrawn from use and the government commenced an investigation.

When people claim that vaccines have “never been tested” they usually mean that they have not undergone randomized placebo controlled trials (RCTs). To do an RCT of a vaccine you would need to take two groups of kids, give one group the vaccine, and the other a placebo, then expose both groups to the disease to see which ones survive. Raise your hand if you can see the problem here…

Not only would such an experiment be unethical, it’s unnecessary. We have extensive evidence demonstrating the effectiveness of vaccines; the eradication of smallpox and the near-eradication of polio from the world are just two examples.

Myth 5: Vaccines don’t work because children who are vaccinated can still get the disease.

No vaccine is 100% effective, and since everybody’s physiology is different, not everyone will develop immunity to the same degree; a vaccine is not a force field. But while you can still breathe in a virus or pick up bacteria off a door handle, the seriousness of the disease will be significantly reduced if you have been vaccinated. In the case of pertussis or whooping cough, severe complications such as seizures and pneumonia occur almost exclusively in unvaccinated people and one in every 200 babies who contract the disease will die.

Also, vaccine-induced and naturally acquired immunity fades over time. Notably, immunity from the whooping cough is not lifelong and infected adults, including child care workers and early years professionals, may be passing the infection on to children. This is why it is so important to get boosters if you are around young kids – especially those who are too young to be vaccinated. If you’re a parent make sure you, the grandparents, and other relatives and friends have boosters before they get to meet baby. Talk to your GP for advice on pertussis boosters (which are free until June 2012 in Victoria).

Myth 6: Improved living standards, not vaccination have reduced disease.

The three most significant factors in the reduction of infectious disease have been clean water, sewerage systems, and vaccination. But even in isolation, vaccination has made a huge dent in reducing rates of disease. Following the introduction of the national meningococcal C immunisation program in January 2003, the number of cases decreased by 39% while numbers of people admitted to hospital with the disease was down by 47%. When the Haemophilus influenzae type B (Hib) vaccination was introduced into Australia in 1992 there was a 94% reduction in cases in children under the age of five (the most frequent illnesses caused by Hib are meningitis, septicemia and pneumonia). Yet living conditions in Australia have changed only marginally since 1992 or 2003. Vaccines have also significantly reduced suffering from the complications of infectious disease. Whilst mortality from polio was less than twenty percent, complications such as paralysis, skeletal deformities, and prolonged immobility during confinement in an iron lung caused significant suffering, all of which were eliminated by widespread vaccination.

Myth 7: Infectious diseases are not serious; children are meant to get them.

Just because they’re called “childhood diseases” doesn’t mean it’s okay for kids to get them and neither are they necessarily benign. Let’s take a look at whooping cough as an example, since Australia has been the grips of an epidemic for several years now.

Whooping cough is much more than “just a bad cough”. Kids often turn blue from lack of oxygen during coughing fits, they may vomit after severe attacks, and even fracture ribs. There is no cure for whooping cough – antibiotics are given to help stop the transmission to others – you just have to hope your immune system can fight it. Severe complications such as pneumonia and brain damage occur almost exclusively in unvaccinated people and in babies under 6 months of age the symptoms can be severe or life threatening. Whooping cough is also known as the 100-day cough making it a chronic and potentially fatal disease.

If you still think infectious diseases are harmless, wander through your local cemetery one day and note how many children died from diseases that we no longer see in society today – stamped out largely due to mass vaccination. Some of us are old enough to remember the images of children in iron lungs and calipers during the scourge of polio, which was wiped out by vaccination.

Myth 8: Vaccines cause or spread the diseases they are supposed to prevent.

Vaccines are not 100% safe – no medical intervention is without risk – and mistakes do happen. In the 1950s in America there was a spate of cases of polio caused by the vaccine, but this was due to a mistake in the manufacturing process and was quickly corrected. Regulations, monitoring and quality control has greatly increased since that time, meaning incidents such as this are very unlikely to be repeated. The risks associated with the disease greatly outweigh the risk from a vaccine.

Myth 9: My child’s immune system will be overwhelmed.

Some parents worry that vaccines weaken or overwhelm the immune system, particularly when given to babies or when multiple vaccines are given at the same time. Children are exposed to many foreign particles on a daily basis through activities such as routine eating, drinking and playing and vaccines contain only a tiny number in comparison to what children encounter every day in their environment. The amount of immune challenges that children fight every day (2,000 — 6,000) is significantly greater than the number of antigens in any combination of vaccines (about 150 for the entire vaccination schedule).

More information: This is certainly not an exhaustive list of myths surrounding vaccination. If you’d like to know more, the following sources contain accurate and easy to read information for parents on vaccination including myths, misconceptions and information about the diseases.

Chain of Protection is an initiative of The National Centre for Immunisation Research and Surveillance (NCIRS) which contains lots of vaccine information, videos and more.

The NCIRS also produce the MMR Decision Aid which is a step-by-step guide to the MMR.

A great general resource for parents wanting to know more about vaccination can be found in the Australian Government publication; Understanding Childhood Immunisation Booklet (highly recommended)

General questions about vaccination can be found on the Australian Governments website; Frequently asked Questions About Immunisation

For more detailed information about vaccines, with references to scientific studies, see the Australian Government’s Handbook; Immunisation Myths and Realities, Responding to Arguments about Immunisation

A complete schedule of the current vaccinations required under the National Immunisation Program can be found here.

Dr. Rachael Dunlop is a medical researcher, science communicator and campaigner for science-based medicine in Australia, with a special interest in the anti-vaccination movement and alternative medicine.   Now working in medical research she is currently focused on the environmental triggers for motor neuron disease with a special interest in toxins found in blue green algae.