Even after someone recovers from polio, they can develop muscle pain, weakness, or paralysis 15 to 40 years later. Children recovering from polio can experience post-polio syndrome as adults, with muscle weakness, fatigue, and joint pain decades after initial infection. It’s not clear why only some people develop post-polio syndrome, but those who have experienced severe cases of polio may be more susceptible.
How is polio spread?
Polio is very contagious. It spreads from person to person, usually when someone comes into contact with the stool of an infected person and then touches their mouth. This is particularly concerning for children under the age of 5, who, Dr. Esper said, may have difficulty with hand hygiene. “Any adult who has children knows that this is how germs are spread,” he said. Less commonly, polio can be spread when droplets from an infected person’s sneeze or cough enter someone’s mouth.
And just like with Covid-19, it’s possible to spread the virus even if you don’t have symptoms.
The oral polio vaccine, which helped eliminate polio in the United States and is no longer administered in the country, contains weakened live poliovirus. In rare cases, the virus can revert to so-called “vaccine-derived polio” and can cause illness, said Dr. Paul Offit, a vaccine expert at Children’s Hospital of Philadelphia. Health officials in New York confirmed that the person in Rockland County was exposed to someone who received the oral polio vaccine, which mutated to a pathogenic form of the virus. The oral polio vaccine has not been given in the United States since 2000. Today, the polio vaccine in the United States is a highly effective injection that does not contain live viruses, unlike the oral vaccine.
There are many countries that still use the oral vaccine. “We are always at risk of that vaccine-derived strain coming into this country,” Dr. Offit said.
How do you protect yourself against polio?
Vaccination is the best way to protect against polio, and the highly effective vaccine is part of a regular childhood immunization schedule in the United States.
“This is the good news of living in the age of vaccines,” said Dr. Offit, who grew up during the 1950s and remembers that his mother forbade him to swim in a public pool for fear of contracting the virus. “You just need to get vaccinated.”