Polio was once one of the nation’s most feared diseases, with annual outbreaks causing thousands of cases of paralysis. Its eradication in the US, officially announced in 1979, is considered one of the country’s greatest public health victories. However, since then there have been occasional outbreaks, often among people who had traveled to other countries. Recently, an unvaccinated young adult in upstate New York contracted polio. On Friday, health officials in the country’s largest city said they found the virus in sewage samples, suggesting it is spreading among the unvaccinated. Here are some details about polio and the vaccine:
HOW IS POLIO TRANSMITTED?
Polio is considered highly contagious and is spread mainly from person to person, through contaminated water and through faecal particles. Health officials say the virus can also spread through droplets from an infected person’s cough or sneeze, though this is less common.
WHAT ARE THE SYMPTOMS?
Most infected people have no visible symptoms. About a quarter will endure a few days of flu-like symptoms, including fever, sore throat, headache and nausea. A small fraction of people, however, can become more seriously ill. The virus can infect a person’s spinal cord, causing paralysis and possibly permanent disability and death.
AREN’T MOST AMERICANS VACCINATED AGAINST POLIO?
Yes. US children are still routinely vaccinated against polio, and the vaccines are considered highly effective. Federal officials recommend four doses: given at 2 months of age; 4 months? at 6 to 18 months; and at 4 to 6 years of age. Some states require only three doses. According to the most recent data from the Centers for Disease Control and Prevention, about 93% of children aged 2 years had received at least three doses of polio vaccine.
IF I GET THE POLIO VACCINATION DO I HAVE TO DO ANYTHING?
For most, no. Adults who were fully vaccinated as children have protective antibodies in their blood for decades, according to the CDC. In a nationwide study of adults aged 40-49 about a decade ago, about 90% had protective antibodies against the virus. That said, health officials have previously recommended boosters in some cases, such as for adults who are at increased risk of coming into contact with the polio virus through travel or work.
WHAT SHOULD I DO IF I HAVE BEEN VACCINATED?
Health officials recommend vaccines to unvaccinated people. In New York, clinics have been set up to distribute the vaccines. People who are unvaccinated or not fully vaccinated are at greatest risk of paralysis from polio. The person in Rockland County diagnosed with paralytic polio was unvaccinated. —— The Associated Press Health & Science Section is supported by the Howard Hughes Medical Institute Science Education Division. AP is solely responsible for all content.
