4 Things You Should Know About Vaccines

It is widely believed by some parents that vaccines will negatively affect their children despite extensive research implying otherwise. This defeats the main purpose of vaccines as they are designed to be used by everyone in a population.

There is a big argument that vaccines should be mandatory, because if a parent decides to risk infection over vaccination for their child they aren’t just risking their own kid’s life but people they come into contact with as well. It is possible they could just carry the disease without being harmed; however it can still infect other people.

I believe parents still deserve a say, so instead of making vaccines mandatory, we should focus on educating parents to make the right decision.

Here I’ve compiled 4 things about vaccines in order for you to get a better idea about their functionality and what you can do to help solve the problem.


  1. What is a Vaccine Exactly?

A vaccine is a virus, or bacterium, that is deliberately administered to you so that your immune system can recognise it and fight it in the case you become infected. This may sound dangerous at first, but the threat of dangerous infection is removed by weakening the viruses and only using parts of bacteria that are harmless, which will allow your immune system to recognise the organism without you experiencing any of its symptoms. Some vaccines must be administered more than once just to be absolutely sure your body is immune to it.


  1. How are Vaccines Tested Before Public Distribution?

Vaccines are created by individual research groups and companies; after they are made they must be approved by the US Food and Drug Administration’s (FDA) Center for Biologics Evaluation and Research (CBER). The sponsor of the vaccine will follow a multi-step approval process which will include:

  • An investigational new drug application
  • Pre-licensure vaccine clinical trials
  • A Biologics License application
  • Inspection of the manufacturing facility
  • Presentation of findings to the FDA’s vaccine advisory committee (VRBPAC)
  • Usability testing of product labelling



After distribution, the FDA will continue to oversee the vaccine to ensure a continued safety. For as long as the manufacturer of the vaccine has a licence to create it, the FDA will have periodic facility inspections.


  1. Why do so Many People Believe They Cause Autism?


In the late 1900s some parents complained their children started developing symptoms of autism after taking Measles/Mumps/Rubella (MMR) vaccines. They reported their children were acting completely “normal” until the vaccination. After receiving the MMR vaccine, their children started showing symptoms autism. Because the symptoms began around the time of treatment, parents saw the cause of their children’s autism to be the vaccination. However just because they both occurring in the same period of time, it does not necessarily mean they are linked.

The media got a hold of this and wrote articles suggesting it was fact and these parents were victims of vaccines. Along with this, the parents observation were backed up by a small research group studying bowel disease and autism, published by Wakefield and his colleagues in 1998. The study’s author suggested a link between the MMR vaccine and autism, however there was no testing or scientific evidence backing this claim.

Not very long later, a few more research groups also suggested a link between the MMR vaccine and autism although they also provided no scientific evidence of such a link.

The reason people still believe this today is that the issue of autism is a very scary and emotional thought that engenders fear in parents and clinicians alike. It seems much more imminent than the threat of a deadly disease after the vaccination and the media takes advantage of this by writing lots of stories about it.

To date there is no solid scientific proof that any vaccines or combination of vaccines can cause autism. They have however been proven to be extremely effective at helping the immune system defend itself against deadly diseases.


  1. Why is it an Issue When Some People Don’t Vaccinate?


It is widely believed that to prevent diseases such as measles, 90-95% of the population must be immunised to achieve what is called herd immunity. This is partially true but is not completely the case. This was calculated assuming immunised and susceptible people are randomly mixed and that vaccine coverage is a perfect measure of immunity in a population. Ideally we would have 100% of the population immunised but some people are either too young or too sick to be vaccinated.

Here I will explain crowd immunity and why it’s very important to aim for 100% immunity. The basic idea of herd immunity is making enough people immune to stop chains of transmission from being established.

We’ll scale down measles just so we can visualise herd immunity, let’s say a newly infected person will spread the disease to two  other people, and those two people will spread it to another two each and so on. Using the same calculation we got 90-95%, in this situation we would need 50% immunised to achieve herd immunity as illustrated by Marcel Salathé below.



If immunisation was completely random in this situation full herd immunity would be achieved as even in the unlikely scenario a chain of transmission were to occur, it would most probably end very quickly.

So looking at measles again, say 95% of the population are immunised; we should be safe right? Well that’s assuming people in the 95% and people in the 5% are completely randomly distributed. In reality there are communities of people who are far less likely to want to get immunised. These communities could be the size of a school or even the size of a state. Here is another illustration by Marcel Salathé (using the 50% example) showing how groups of susceptible people will change the figures of how many people are needed to achieve herd immunity.



As long as there are groups of people refusing to immunise, this will still be a problem. What we need is everyone who can vaccinate, should vaccinate – not only to protect themselves but the people around them too. One immunisation can prevent and entire chain of transmission.


by J.D.










Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s