Common Vaccine Misconceptions

Renata Zgraja

Pro-Vax has sought public opinion to unearth the main reasons people may be concerned with undergoing vaccination. Following a recent Facebook poll and input from information sought from the World Health Organization [1] , the following common 7 concerns regarding vaccines were identified:

#1 Vaccines have been linked to Autism

The link between vaccines and autism first occurred in 1998 when Andrew Wakefield alluded to (in his fraudulent, now retracted research paper!) that there was a causative link between Autism Spectrum Disorder and the combined Measles, Mumps and Rubella (MMR) vaccine. Of course, since then, society has exercised caution towards vaccination due to the belief that vaccination leads to the development of autism. In his paper, Wakefield suggested that the MMR vaccine can cause autism through three main mechanisms, these being:

• The MMR vaccine damages the intestinal lining and consequently allows for the entrance of encephalopathic proteins [2]. Multiple studies have been conducted since these claims and no toxic encephalopathic proteins travelling from the intestine to the brain have ever been identified [2].

• Thiomersol (a mercury compound used as a preservative within the vaccine) leads to central nervous system toxicity [2]. It is interesting to note that the MMR vaccine mentioned in Wakefield’s paper is a live vaccine and these types of vaccinations did not even contain thiomersal as preservatives [2]! However, since the year 2000, vaccines found on Australia’s National Immunisation program are thiomersal free [3]. Not only did this occur in Australia but other countries as well - if there was in fact a causative link between thiomersal and Autism Spectrum Disorder then a decrease in the incidence of Autism should have been observed but evidence from several studies examining trends in vaccine use and the incidence of autism do not support such a relationship [4].

• Multiple vaccinations overwhelm and weaken the immune system [2]. It is remarkable that during the 1980s vaccines were given separately but contained more than 3000 immunological components between the 7 available vaccines [2]. Today, there are 14 recommended vaccinations but these contain less than 200 immunological components between them, suggesting that combination vaccines won’t overwhelm the immune system [2]. Furthermore, an infant is ‘naturally’ exposed to thousands of antigens in early life which suggests there is no need for concern when it comes to immune system overload after vaccination [2].

Andrew Wakefield’s paper was retracted from the Lancet in 2010 [2], but despite this, the reputation of vaccinations remains tainted even with multiple studies, such as the ones encompassed within the 2012 Cochrane review, consistently demonstrate that exposure to the MMR vaccine is unlikely to be associated with autism [5].

#2 Vaccines contain harmful additives

As mentioned above, vaccinations used to contain thiomersal, however, this is not the case anymore. Since 2000, there have not been any vaccines on the Australian National Immunisation program which contain mercury and this is because vaccines now come in single seal vials which do not require added preservatives [3]. Similarly, the United States have removed thiomersal from almost all vaccines ,except for one type of influenza vaccine, but thiomersal free alternatives are available [4]. Vaccines may also contain other substances such as gelatin and albumin to ensure they remain stable for a longer period of time [3]. Although not harmful, albumin may pose a concern to members of certain religious groups which prevent the administration of any blood products. Vaccines may also have residual traces of formaldehyde, antibiotics, egg and yeast proteins from their manufacture. Whilst these shouldn't be a cause for concern for the general population, individuals with allergies to egg and yeast should exercise caution [3]. Finally, some vaccines contain aluminium salts to enhance their immune response and whilst high levels of aluminium can lead to toxicity, these vaccinations (e.g. diphtheria, tetanus & pertussis vaccine) contain less aluminium than an antacid used to relieve heart burn! [3]

#3 Vaccines cause side effects and spread the disease they are meant to prevent

Most vaccinations used in Australia contain inactive parts of the pathogen and as such cannot cause disease [3]. However, some vaccines contain live attenuated viruses and even though the virus is weakened it can (very rarely!) lead to the development of the disease [3]. Examples of vaccinations which contain live viruses are the MMR vaccine for Measles, Mumps and Rubella as well as the BCG vaccine used for tuberculosis [3].Another common misconception is that the influenza vaccine causes the flu. In Australia, the flu vaccine is composed of inactive virus particles which are UNABLE to replicate within the body meaning they cannot lead to development of the flu [3]. However, feeling unwell after the administration of the influenza vaccine can be due to mild, post-vaccine side effects or an infection from a different respiratory virus [4]. Both of these have the ability to cause flu like symptoms [3]. Also it takes 7-14 days following vaccination to develop immunity to the influenza virus, so if a person comes into contact with virus before this period they can become infected [3].

#4 Multiple vaccines can overwhelm the immune system

In a healthy individual, vaccines do the opposite and STRENGTHEN the immune system by stimulating it to produce antibodies [3]. These antibodies form part of an immune response and allow the body to protect itself against disease [6]. When a person is vaccinated, they are administered a small amount of the disease causing pathogen which can be easily overcome by the immune system [6]. However, one of the major benefits of vaccination is that it allows this response to be remembered and ensures a much faster, greater and more sustained immune reaction is produced upon subsequent encounters with that particular pathogen [7]. This allows for the infection to be controlled more efficiently and prevents any serious and severe symptoms associated with the disease [6]. Newborns are a little bit more complicated because even though the immune system starts developing during pregnancy it is not fully mature at the time of birth [3]. However, newborns are protected against many infections because of the antibodies they have acquired from their mothers [3]. Sadly, all good things must come to an end with this protection only lasting for a period of 4 months [3]. However, do not despair because the National Vaccination Program has been designed in such a way that balances the capacity of the baby's immune system to respond to the vaccine and the risk of infection [3]. Following the vaccination schedule allows the child’s immune system to not become overwhelmed [3].Additionally, not only do vaccines contain a small number of antigens compared to the antigens children are exposed to on a daily basis (through eating, drinking and playing) [3], today’s vaccines contain less than 200 immunological units [2] to ensure children are not exposed to dangerous amounts of antigens at one given time.Another concern for parents is that some vaccines are administered as a combination (for example the measles, mumps and rubella vaccine) and may overwhelm the immune system. These vaccinations are tested to ensure that the same immune response is elicited when the vaccinations are administered in combination and when they are given separately [3]. It is also ensured that the immune responses to each of the antigens within the vaccine is appropriate and adequate to provide immunity later on in life [3].

#5 It is better to obtain immunity of a disease naturally than through vaccination

'Natural' immunity results from the survival of a natural infection rather than from the administration of a vaccine. Natural immunity can be beneficial in some instances as it can last longer than vaccine-induced immunity but in the case of Haemophilus Influenzae type b and tetanus, vaccine acquired immunity is more effective [9].Regardless of this, the risks associated with natural infection are far greater than the risks of immunisation [9]. Choosing to remain unvaccinated can have some serious repercussions! Some diseases like tetanus and meningitis are potentially deadly whilst their vaccinations are generally well tolerated by the public with minimal side effects [3]. Also, vaccines provide the immune system with the same stimulus as the naturally occurring infection but in a weaker or smaller dose [3] .

#6 More vaccinated people get the disease than unvaccinated people

Unfortunately vaccinations do not provide complete protection against a disease [9]. This can be attributed to the fact that vaccines use dead or weakened bacteria or viruses to ensure safety. Also, individual genetics may prevent the development of successful immunity following vaccination [3].However, the idea that more vaccinated than unvaccinated individuals contract the disease is simply a numbers game. In a hypothetical population of 1000 people, there may only be 980 vaccinated and 20 unvaccinated individuals [9]. This type of distribution is commonly seen in countries such as Australia, where the number of vaccinated individuals for common, vaccine-preventable, childhood diseases greatly exceeds the unvaccinated population [3]. However, different vaccines provide different rates of protection and potentially only 98% of the vaccinated population may have gone on to successfully develop immunity against the disease [9]. Most routine childhood vaccines are effective within 85-95% of the vaccinated population [3].If an outbreak of the disease was occur all of the unvaccinated people (providing they had not come into contact with the disease previously [3]) would get sick BUT only 2% of the vaccinated population would go on to develop the illness [9] (this equates to approximately 20 people).Does this mean that vaccination is ineffective because there were 20 people from both the vaccinated and unvaccinated populations becoming ill? No. This is due to the fact that these figures are incomparable unless interpreted as a percentage. When this occurs, the numbers show that only 2% of vaccinated individuals contracted the disease as opposed to 100% of the unvaccinated population.

#7 As long as other people are vaccinated, I don't have to be

Vaccination provides more beneficial outcomes when a certain percentage of the population is immunised as this leads to the development of ‘herd immunity’ [7]. If no one is immunised then the disease will spread rapidly through the community [7]. If only some of the population is immunised then the disease will spread through some of the population [7]. However, if most of the population is immunised then the disease will be contained [7]. Even though the disease will still be contained if the majority of the population is immunised, the best way to ensure YOU avoid the disease is by being part of this vaccinated majority because the main purpose of vaccines is to protect the vaccinated individual against the target infection [8]!

References

1. World Health Organisation . What are some of the myths – and facts – about vaccination? . 2013 [cited 2014 March]. Available from: http://www.who.int/features/qa/84/en/

2. Dachs R, Darby-Stewart A, Graber MA. Autism and Childhood Vaccinations: Debunking the Myth. American family physician. 2010;82(6):586-592.

3. Australian Government Department of Health and Ageing. Myths and Realities: Responding to arguments against vaccination. A guide for providers. 5th ed2013

4. Centers for Disease Control and Prevention. Vaccine Safety. Atlanta; 2014 [cited 2014 March]. Available from: http://www.cdc.gov/vaccinesafety/concerns/autism/

5. Demicheli V, Rivetti A, Debalini MG, Di Pietrantonj C. Vaccines for measles, mumps and rubella in children. Evidence‐Based Child Health: A Cochrane Review Journal. 2013;8(6):2076-2238.

6. Australian Academy of Science. The Science of Immunisation. Canberra; 2012.

7. National Institute of Allergy and Infectious Disease. Community Immunity ("Herd" Immunity). USA; 2010 [cited 2014 March]. Available from: http://www.niaid.nih.gov/topics/pages/communityimmunity.aspx

8. Smith PG. Concepts of herd protection and immunity. Procedia in Vaccinology. 2010;2(2):134-139.9. College of Physicians Philadelphia. History of Vaccines. Philadelphia; 2014 [cited 2014 March]. Available from: http://www.historyofvaccines.org/content/articles/misconceptions-about-vaccines

#autism #vaccines #sideeffects #immunesystem #herdimmunity