Why has polio been in the news lately? A case was detected in New York in July, along with traces of the virus in the local sewage water. This patient had not been vaccinated against polio, and likely contracted it from someone outside of the country. Should we be concerned about a resurgence, and yet another pandemic?
Poliomyelitis has been a cause of life-threatening paralysis for thousands of years. At the height of the biggest outbreak in 1952, almost 60,000 cases, including over 3,000 deaths, occurred in the U.S. alone. A famous victim of polio was our 32nd president, Franklin D. Roosevelt, who became paralyzed at the age of 39, in 1921.
This country has been free of naturally occurring cases of polio since 1979, and the world had come close to achieving complete eradication. Two interventions are responsible for eliminating polio: vaccines and clean water. However, there has been a rebound in polio cases worldwide due to several issues: a pause in global vaccinations during the initial phase of the COVID-19 pandemic, the recent surge of vaccine hesitancy, and the war in the Ukraine and other political hotspots.
Polio typically affects children under the age of five, though anyone who is unvaccinated can contract it. Its initial symptoms include fever, fatigue, headache, vomiting, stiffness of the neck and pain in the limbs. Note that most infections have no symptoms at all, and only 1 in 200 leads to irreversible paralysis (usually in the legs). Among those who become paralyzed, 5-10% die (the breathing muscles become paralyzed). Children who recover from paralytic polio may then suffer from post-polio syndrome, symptoms which appear many years after recovery.
Cases sharply declined after immunizations became widely available. The oral polio vaccine, developed by Albert Sabin in the 1950s, used a live, but weakened, form of the virus. I recall lining up for this vaccine at school, delivered in a cube of sugar! A second polio vaccine was developed by Jonas Salk, and contained inactivated or dead poliovirus. More than 120 countries routinely inject this safe and highly effective vaccine, usually to children between the ages of two months to six years.
The CDC now recommends a one-time booster shot for those traveling to areas where polio is epidemic or endemic, for health care workers who have close contact with certain patients, and for unvaccinated adults whose children will be receiving the oral (live) vaccine.
The bottom line? Those of us who are vaccinated need not worry about polio. The vast majority of people here in the U.S. have been vaccinated, with 93% of our children being vaccinated by the age of two. The unvaccinated include those children who live in a state that does not require the vaccine to attend school, or who have been granted a religious exemption. (Note that low rates of routine pediatric vaccinations within communities in the New York area were responsible for the major 2018-2019 measles outbreak.)
We have come close to eradicating polio across the globe. Unfortunately, it remains in impoverished countries that struggle with vaccination rates and clean water. Let’s keep our country safe through vaccinations, and let’s hope for success in finally eradicating this terrible disease.