Happy Immunization Month! This is a month where we talk about the importance of immunizations, and why they are by far one of the most significant human achievements in history!
I am beginning a series of posts to inform everyone about what vaccines are and why they work. This may serve as ammunition in any sort of a Facebook or Twitter feud one might find themselves in against some anti-vaccination activists, or as a simple reminder of the wonder that is the modern vaccine. Remember, knowledge is the best weapon against ignorance. So, bookmark my blog and make yourself comfortable. Class is now in session.
To understand vaccinology we first need to understand why we vaccinate and how we vaccinate. To talk intelligently about a subject, it is convenient to define some terms and make a few things clear for later lessons.
A vaccine is a term used to group together a number of methods for priming the immune system against a pathogen with the intention of preventing the development of an infection. I will go into detail about the types of vaccines in a later post, but for right now understand that they make the immune system respond to a specific pathogen (like the flu virus, or measles, or small pox, etc.).
Intentional vaccination (as compared to simply acquiring a disease and becoming immune) was first researched by Edward Jenner, a English medical student. In the late 1760’s, smallpox was a serious problem in England, and while studying the disease, Jenner heard of stories that milk maids who had contracted cowpox did not contract smallpox. To test this, he intentionally infected a healthy 8-year-old boy with cow pox, and then exposed him to smallpox. Luckily, this all-or-nothing bet paid off, and the boy did not get sick.
From this test came not only the idea of vaccination, but also the word “vaccine” from the latin word meaning cow. It took until 1880, when Louis Pasteur created vaccines against cholera and anthrax, before major vaccine development began. Although some examples exist of techniques similar to vaccination being practiced by the Chinese as early as 1000 A.D., modern vaccines are frequently recognized as a product of English research.
The 20th century brought vaccines against a number of significant diseases, including Hepatitis B, tuberculosis, yellow fever, influenza, polio, measles, mumps, rubella, cholera, and leishmaniasis, among others. In 1980, the World Health Organization declared that smallpox had been eradicated, and polio had been wiped out in the Western nations by the turn of the century. Vaccines were working, mostly because in many places they were becoming the norm, if not mandatory.
Even though not every single person was vaccinated, the vast majority of people were, allowing for something called herd immunity. The concept is that because there are so few susceptible hosts in a population, even if one person is infected the disease does not spread from one person to another. This stops the disease in its tracks, and small outbreaks can be contained and eliminated from the larger population as a whole. This method only works, however, if the vast majority of people are immunized, and if pockets of non-immunized individuals don’t exist.
Ok students, the bell is about to ring, and that is all the time we have for today. I hope you took good notes. Tomorrow, we will be going through the types of vaccines, and how vaccines are developed. I hope you come back for more!
Question of the day: if you had to pick one disease to contract that is currently vaccinated against, which would it be and why? Answer in the comments!
