Why Vaccinate?
There’s a large movement of parents who choose not to vaccinate their children against preventable diseases like measles, whooping cough and chicken pox. Misinformation and misunderstanding about what a vaccine is, how it works, how it affects the population and what are the downsides all impact the choices parents make. Let’s explore these…
What is a vaccine?
A vaccine introduces a weakened version of a deadly virus into your body in order to jump start the body’s natural disease-fighting mechanisms, which are already remarkably effective. When the weakened virus in a vaccine enters your body, your immune system gets to work. White blood cells identify the virus as foreign and produce antibodies that are specifically designed to fight off that particular virus. Because the vaccine uses weakened or even dead fragments of the actual virus, you develop the antibodies but you do not suffer the full effects of the disease. Once the antibodies are in your system (remember, it’s your own body that produces the antibodies, just like it would if you came down with chicken pox in the old fashioned way), you have a built in defense against a future real attack by the virus, be it diphtheria, measles or the flu. Like many scientific advances, a vaccine is a remarkable improvement on what nature already does.
What is Herd Immunity and why is it important?
A virus needs a human host to reproduce. Groups of people, living closely together, sharing dishes, towels, and bathrooms, shaking hands and hugging each other, are perfect breeding grounds for viruses. The viruses are transmitted from person to person, and the more people that can act as hosts, the quicker they propagate. If everyone in a group is absolutely immune to a particular virus, it has no chance to survive and it will be contained. If everyone is susceptible, the virus will spread easily, becoming an outbreak. The more people are immune, the easier it is to contain a viral outbreak. “Herd immunity” is when enough people in a group (the “herd”) are vaccinated that those who are not vaccinated are protected, too, because is contained when there are too few human hosts.
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vaccines: victims of their own success |
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| Ironically, it is because vaccines have been so successful – drastically reducing the number of people affected by diseases – that it could seem like they’re not necessary. Most people in the first world have never seen someone die from a preventable disease.
Before the measles vaccine, for example, 90% of the population of the US came down with measles by age 15. In the years after the MMR vaccine was developed, the incidence of measles decreased by 95%. Some diseases, such as Polio, have been completely eradicated. Following the licensing of each particular vaccine, incidence of the disease drops. |
Herd immunity matters because there are people who cannot tolerate a vaccine; if their own immune system is compromised, or they are allergic to an inactive ingredient in the vaccine, for example. In order to protect these people who cannot be vaccinated, most of a population needs to be vaccinated – you must have herd immunity.
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Herd immunity in action |
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| What happens when too few people are vaccinated to generate herd immunity? One example comes from Japan in 1974, when 80% of people were vaccinated against whooping cough. In that year, there were only 393 cases of whooping cough reported in the entire country and no deaths.
By 1976, rumors began that the vaccination was no longer needed and was actually unsafe, and by 1976 only 10% of children were vaccinated. By 1979, a whopping cough epidemic occurred where 13,000 people came down with whooping cough and 41 died. |
Given how well vaccines work, why would you choose not to vaccinate? Some people who do not vaccinate claim that vaccines are “artificial” and that it is better to let the body fight off diseases by itself. This is a misunderstanding of how vaccines work. Vaccines are a way to help your body do what evolution has enabled it to do so well. Giving it a little boost to fight attacks by a virus. Vaccines work because the human immune system works.
Vaccinations and autism: a red herring
A fraudulent 1998 paper in the Lancet gave support to the erroneous claim that autism spectrum disorders were linked to the measles, mumps and rubella (MMR) vaccine. The studies have been renounced by the Lancet, but it is worth examining why the mistaken idea that vaccines cause autism persists.
Key is the distinction between “commonality” and “causation.” If two things are related by commonality, they occur together, possibly because of some underlying cause. For example, people in New England are often seen outside in the winter wearing both winter coats and winter hats. They didn’t put on hats because they were wearing a coat. They are wearing both coats and hats because it is cold outside.
Causation, on the other hand, is when two things occur together because one causes the other. Cold outside temperatures and winter coats are causally related because you don that coat when it is cold outside. But winter coats and winter hats are not causally related, even though they often occur together.
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Connection is not causation! |
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| It is easy to imagine how a connection between autism and vaccinations could anecdotally be seen as a cause. Imagine you had a baby, and she was quickly given quite a number of vaccinations. If your baby later developed autism, which tends to appear around the time babies are getting their second big round of shots, and you were already suspicious of vaccines, it would be easy to make the leap that the vaccinations (which came first) caused the autism.
However, it could be that they were connected instead. Maybe there is an underlying genetic mutation responsible for autism that also has the effect of causing a negative reaction to vaccines (so you would already view vaccinations negatively). Or maybe there is something in the environment (excess chemicals in our food, or water, or air, for example) that came about around the time vaccines were developed that is also related to autism. There are many ways that autism and vaccines can be connected without being causal. |
Multiple studies completed since the original paper confirm that the rates of autism are the same in vaccinated versus un-vaccinated children (http://www.jpeds.com/article/S0022-3476(13)00144-3/pdf?ext=.pdf).
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Real science |
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| Science shows that vaccinating your child is as likely to lead to autism as putting on a winter coat is to lead to putting on a winter hat. If you want to avoid getting hat hair from that hat, you had better move to a warmer climate rather than stop wearing the winter coat. |
Why I vaccinate my children
If you don’t want your child or others to suffer or die from a preventable disease, you need to vaccinate. Embrace this miracle of modern medicine and feel lucky that your children will almost certainly suffer from a small needle prick rather than a deadly disease.
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Why vaccinate? TL;DR |
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Don’t take my word for it… See this article by the Center for Disease Control. |