Of all of the inventions on my revised top ten list, vaccines are my favorite. Vaccinations are an incredible medical development that not only serve as a preventative treatment to many deadly diseases, but they set precedent for what is now known as the field of preventative medicine.

In the simplest of terms, vaccines are made of pieces of or weakened versions of infectious agents (viruses or bacteria). Vaccinations take advantage of the immune system's innate ability to develop immunity and as a result prevent the spread of certain diseases.

Throughout the course of history, vaccines have played a revolutionary role in minimizing, and even eradicating, infectious disease. Vaccines have minimized diseases such has small pox, polio, whooping cough, and measles.



Furthermore, the impact of vaccines is not limited to infectious disease. Certain viruses, like the Human Papilloma Virus (HPV), are responsible for cancers. By creating vaccines for such viruses, the rate of cancer can be reduced as well.

It's also important to note that the impact of vaccines is not on an individual scale. With the majority of a population becoming vaccinated, there is a synergistic impact of vaccines; vaccinations prevent public health epidemics on a global scale.

As preventative measures, vaccines are debatably one of the earliest manifestations of the field of preventative medicine. Vaccines are arguably cost-efficient on a consumer level because as preventative measures, they prevent the need for costly drugs to treat disease.

A tangental note on preventative medicine: MIT economist and MacArthur genius awardee Heidi Williams has published an interesting study analyzing the impact of the patent system, interfacing with a regulatory agency, the FDA, on incentives to innovate cancer drugs. Williams finds that the economic incentives created and perpetuated by the patent system and the FDA incentivizes the innovation of cancer drugs that extend the lives of patients by months over the innovation of preventative cancer measures. Given the amazing potential of  preventative measures to revolutionize public health, as exhibited by vaccines, this finding may be at odds with the direction that the pharmaceutical and biotech industries should be going.

Sources: 
http://vaccineresistancemovement.org/wp-content/uploads/2010/05/Universal-Flu-Vaccine1.jpg
http://www.nytimes.com/2015/12/29/upshot/why-preventing-cancer-is-not-the-priority-in-drug-development.html
http://www.vaccines.gov/images/measles.jpg
https://larissaf15.files.wordpress.com/2011/04/22333_247185629752_247135464752_3258194_4603383_n.jpg