Reducing and eliminating the diseases that vaccines prevent is one of the top achievements in the history of public health. But some how the number of anti vaccinators increased from the past. Its mainly through the widespread of news regarding misconceptions of vaccines. The widespread fear that vaccines increase risk of autism originated with a 1997 study published by Andrew Wakefield, a British surgeon. The article was published in the Lancet, a prestigious medical journal, suggesting that the measles, mumps, rubella (MMR) vaccine was increasing autism in British children. But later this paper was completely discredited due to serious procedural errors. Its publication set off a panic that led to dropping immunization rates. However that went unnoticed by many as usual and still rumours continue to spread.
Vaccines need additives to improve the way they work, increase their shelf life and make them as safe and effective as possible. The three main substances added to vaccines are:
- adjuvants or enhancer– to make the vaccine more effective
- stabiliser – to stop the vaccine deteriorating when it is exposed to changes in the environment, such as light and temperature
- preservatives– to increase the vaccine’s shelf life.
Any licensed vaccine is rigorously tested across multiple phases of trials before it is approved for use, and regularly reassessed once it is on the market. Scientists are also constantly monitoring information from several sources for any sign that a vaccine may cause an adverse event. Most vaccine reactions are usually minor and temporary, such as a sore arm or mild fever. In the rare event a serious side effect is reported, it is immediately investigated. So available vaccines remain safe.
Common Myth is that: Vaccines can cause autism bacause they contain ingredients that are dangerous. The most often blamed culprit is thimerosal.
Thimerosal, which is approximately 50% mercury by weight, has been one of the most widely used preservatives in multi-dose vaccines. It is metabolized or degraded to ethylmercury and thiosalicylate. Ethylmercury is an organomercurial that should be distinguished from methylmercury, the chemical actually known to cause harm. Methylmercury is the type of mercury found in certain kinds of fish. At high exposure levels methylmercury can be toxic to people. But over a lifetime, everyone is exposed to some methylmercury through food and environment. The different type of mercury in thiomersal has the ability to be metabolised at a faster rate and they get excreted quickly from our body. Thus thiomersal is less likely to produce harmful effects on the human body.
Thimerosal is used to prevent the growth of microbes during the manufacturing process.. Thiomersal is more commonly used in mixed dose vaccines. Live and single dose vaccines do not necessarily need agents like Thimerosal. When each new needle is inserted into the multi-dose vial, it is possible for microbes to get into the vial. The preservative, thimerosal, prevents contamination in the multi-dose vial when individual doses are drawn from it. Receiving a vaccine contaminated with bacteria can be deadly.
In developing countries like India, multi dose vaccines are still being used at large as these countries cannot afford to make single dose vaccines and not to use preservatives like thiomersal. The cost of producing single dose vaccines and the need to refrigerate them for proper storage and transport makes the use of thiomersal absolutely necessary. However, USA and some countries have decreased the use of thiomersal in vaccines only as a precaution. But even in those countries, it’s use has not been discontinued altogether.
Research indicates there is no difference in the rates of autism between vaccinated and unvaccinated children. While autism may seem more common in recent years, This is because the diagnosis of autism now includes children with milder symptoms who would not have been included in the past. There is also greater public awareness of autism, and more parents are seeking help. Even today the true causes of autism remain a mystery, but to the discredit of the autism-vaccination link theory, recent studies provides evidence that autism develops in utero, well before a baby is born or receives vaccinations. There is no evidence of a link between MMR vaccine and autism or autistic disorders. Still anti-vaccine ideologists uses ”thiomersal” and “mercury poisoning” as their main weapon for propagating base-less ideas and creating alarm in minds of parents.
Another myth is that Babies Immune system get overloaded with vaccines. Based on the number of antibodies present in the blood, a baby would theoretically have the ability to respond to around 10,000 vaccines at one time. Even if all 14 scheduled vaccines were given at once, it would only use up slightly more than 0.1% of a baby’s immune capacity. And scientists believe this capacity is purely theoretical. The immune system could never truly be overwhelmed because the cells in the system are constantly being replenished. In reality, babies are exposed to countless bacteria and viruses every day, and immunizations are negligible in comparison.
WHO has closely monitored scientific evidence relating to the use of thiomersal as a vaccine preservative for over 10 years, in particular through its independent expert advisory group, the Global Advisory Committee on Vaccine Safety. The Committee has consistently reached the same conclusion: there is no evidence to suggest that the amount of thiomersal used in vaccines poses a health risk. Immunization with thiomersal-containing multi-dose vaccines currently protects at least 64% of all infants and children against four diseases with high mortality rates: diphtheria, tetanus, pertussis and Haemophilus influenza type b. The use of thiomersal-containing vaccines to protect against these diseases averted at least 1400000 child deaths in 2010. Thiomersal-containing vaccines are being used in over 120 countries. Removing thiomersal completely from vaccines would require either using alternative preservatives or using preservative-free single dose vaccines exclusively. Alternatives would incur significant costs for development and regulatory approval, thereby limiting the ability to offer affordable vaccines.
Immunisation is one of our most significant achievements. It saves around 3 million lives world-wide each year and helps to prevent outbreaks and hospitalisations from vaccine-preventable diseases. As a parent its your duty to protect your child by ensuring vaccines are given on time. Vaccine-preventable diseases are still common in many countries. Increased travel and immigration means the risks are real.
In reality, the benefits of vaccination greatly outweigh the risk i.e., having a vaccination is much safer than not having one. They’re not 100% effective in every child, but they’re the best defence against the epidemics that used to kill or permanently disable millions of children and adults. Choosing to protect your child with vaccines is also a choice to help protect your family, friends, and neighbours. i.e. to get vaccinated means to protect ourselves and to protect those around us. Successful vaccination programmes depend on the cooperation of every individual to ensure the well being of all. We should not rely on people around us to stop the spread of disease; we, too, must do what we can.