Polio, also known as poliomyelitis, is a highly contagious disease caused by the poliovirus. It primarily affects children under the age of five, and in severe cases, it can cause paralysis and even death. Thankfully, the polio vaccine has been extremely effective in preventing the spread of this disease. In this article, we’ll explore the history of the polio vaccine, how it works, and its effectiveness.
The History of Polio and the Need for a Vaccine
The first polio epidemic in the United States occurred in 1894, but it wasn’t until the 1950s when the disease caused widespread panic. During this time, the United States saw an average of 35,000 cases of polio each year. It was considered one of the most dreaded diseases of the time, as it could lead to lifelong paralysis and even death.
In 1955, Dr. Jonas Salk developed the first polio vaccine using a killed virus. The vaccine was highly effective in preventing the disease and was widely distributed. As a result, the number of polio cases in the United States decreased dramatically.
Types of Polio Vaccine
There are two types of polio vaccine: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). The IPV is given as an injection, while the OPV is given orally.
The IPV is made up of killed poliovirus, and the OPV is made up of a weakened form of the virus. Both vaccines are highly effective in preventing polio, but there are some differences in the way they work.
How Does the Polio Vaccine Work?
The polio vaccine works by teaching the body’s immune system to recognize and fight the poliovirus. When the body is exposed to the virus through the vaccine, the immune system produces antibodies to fight the virus. If the person is exposed to the actual virus later on, their immune system is already primed to fight the infection.
Effectiveness of the Polio Vaccine
The polio vaccine is one of the most effective vaccines ever developed. When given in the proper doses, the vaccine provides almost 100% protection against all three types of poliovirus. According to the World Health Organization (WHO), the polio vaccine has saved millions of lives worldwide.
Thanks to the effectiveness of the polio vaccine, the number of polio cases has decreased dramatically over the last several decades. In fact, the Americas were declared polio-free in 1994, and Europe was declared polio-free in 2002.
Many countries in Asia and Africa are still working to fully eradicate the disease, but with the help of organizations like WHO and UNICEF, progress is being made. In 1988, there were an estimated 350,000 cases of polio worldwide. In 2019, that number had dropped to just 175.
Polio Vaccine Side Effects
Like all vaccines, the polio vaccine can cause side effects. However, these side effects are generally mild and go away on their own. The most common side effects include:
- Pain, redness, or swelling at the injection site (for the IPV)
- Mild fever or headache
In very rare cases (less than 1 in 1 million doses), the oral polio vaccine can cause paralysis. This is known as vaccine-associated paralytic polio. However, this risk is much lower than the risk of getting polio from the actual virus.
To ensure continued protection against polio, it’s important to receive booster shots throughout your life. In the United States, the recommended schedule is four doses of the IPV. The first three doses are given during infancy, and the fourth dose is given between the ages of four and six.
The polio vaccine has been one of the greatest public health achievements of the past century. It has saved countless lives, and it continues to do so today. The vaccine is highly effective, and while it can cause mild side effects, they are generally outweighed by the benefits of vaccination.
- How effective is the polio vaccine?
- What are the side effects of the polio vaccine?
- Is the polio vaccine still necessary?
- What countries are still affected by polio?
- What is the difference between the IPV and OPV?
The polio vaccine is almost 100% effective when given in the proper doses.
The most common side effects include pain, redness, or swelling at the injection site (for the IPV) and mild fever or headache. In very rare cases, the oral polio vaccine can cause paralysis.
Yes, it’s important to receive booster shots throughout your life to ensure continued protection against polio.
Many countries in Asia and Africa are still working to fully eradicate the disease.
The IPV is given as an injection, while the OPV is given orally. The IPV is made up of killed poliovirus, and the OPV is made up of a weakened form of the virus.
World Health Organization. (2021). Poliomyelitis. https://www.who.int/news-room/q-a-detail/poliomyelitis
Centers for Disease Control and Prevention. (2021). Polio & Vaccination. https://www.cdc.gov/vaccines/vpd/polio/index.html
History of Vaccines. (2021). Polio. https://www.historyofvaccines.org/content/articles/polio