Polio Vaccine: A Brief History
Polio, also known as poliomyelitis, is a viral infection caused by a type of virus that lives in the throat and intestinal tract. While, it mainly affects young children, it can also affect adults and can lead to paralysis, respiratory failure, and even death. Fortunately, one of the biggest medical breakthroughs of the 20th century was the development of the polio vaccine, which has helped to dramatically reduce the mortality rate due to this devastating disease. In this article, we will take a look at the history of the polio vaccine and how it changed the world forever.
Early Attempts to Develop a Polio Vaccine
The idea of polio vaccination first came about in the late 1800s when Louis Pasteur proposed the concept of “attenuation” – exposing a live pathogen to certain conditions to weaken it so that it can no longer cause disease, but still offer immunity. Pasteur himself began to develop a vaccine against chicken cholera and soon after, the goal of developing a polio vaccine emerged as well. In 1908, researchers discovered that polio was caused by three different viruses, and it was also discovered that artificially weakened forms of these viruses could protect people from the disease.
Jonas Salk and the Development of the First Vaccine
In 1952, Jonas Salk began developing his own vaccine against polio based off of the research conducted by Dr. Thomas Francis, Jr from the University of Michigan. Salk’s vaccine included inactivated, or dead, strains of the polio virus, as opposed to the weakened, or live, strains used by Pasteur. To create the vaccine, Salk used formaldehyde to kill off the virus, which ensured it was no longer contagious.
In 1954, the vaccine was tested on over 1.8 million people in a large-scale trial funded by the National Foundation for Infantile Paralysis (today known as the March of Dimes). The results of the trial indicated that the vaccine was safe and effective, and it was approved by the U.S. Food and Drug Administration in 1955.
Albert Sabin and the Live Polio Vaccine
Following Salk’s success, another researcher named Albert Sabin began working on a live polio vaccine as well. He developed a weakened version of the polio virus that was orally administered, as opposed to Salk’s version which was injected. In 1961, his vaccine was tested on a large population of children in the Soviet Union and it proved to be effective as well.
The Vaccine Begins to Reach the Global Population
In 1962, the World Health Organization (WHO) began to promote the use of both the Salk and Sabin vaccines in order to reach even more people with the life-saving relief from polio. The global vaccination program began in 1974, and it was incredibly successful, helping to reduce the number of cases from 350,000 in 1988 to just over 1,000 in 2017.
Who Was Most Impacted by the Introduction of the Polio Vaccine?
It goes without saying that the polio vaccine has saved countless lives and spared many from long-term disability. But, perhaps the most significant population to benefit from the polio vaccine was the young children of the developing countries, who are especially susceptible to the virus due to malnutrition and unhygienic living conditions.
For instance, in India, the introduction of the polio vaccine led to a dramatic decrease in the number of cases. In the mid-1980s, the country had the highest number of reported polio cases in the world but by 2012, it had been declared free of the disease. This was thanks, in part, to two large-scale vaccination campaigns which reached over 170 million children under age five.
Polio Vaccine’s Continuing Impact
Today, the number of cases of polio are at an all-time low and the disease has been eradicated in many countries. However, there is still work to be done. Currently, four countries remain endemic for the virus— Afghanistan, Nigeria, Pakistan and Afghanistan — and there are also still cases in 21 other countries.
In addition, there is an ongoing effort to reach and vaccinate children in those areas and throughout the world. In order to further this effort, vaccine programs provide the vaccines for free, as well as other efforts such as vaccinating crossing points on borders and during large-scale events, such as sporting and religious gatherings.
The successful development and introduction of the polio vaccine has made a lasting, positive impact on the world. For instance, the vaccination campaigns have led to a drastic drop in the number of polio cases, and the disease has been eliminated in many regions of the world. It is a success story that shows the power of the human spirit and the commitment of the medical community to eradicate diseases and save countless lives. Polio is still a threat in some parts of the world, but with continued research and effort, we may one day see its complete eradication.
