Why polio has reemerged, and how to stay safe: Experts advise
In the 1950s, the United States experienced a large outbreak of poliomyelitis (polio) — a viral infection causing paralysis, breathing issues, and possibly death. At the peak of the outbreak in 1952, there were about 20,000 casesTrusted Source of polio in the country.
In 1955, the first polio vaccineTrusted Source — known as the trivalent inactivated poliovirus vaccine (IPV) — became available. Widespread vaccination helped lower the number of polio casesTrusted Source each year in the U.S. to less than 100 in the 1960s and less than 10 in the 1970s.
All U.S. states currently require children to receive polio vaccinations to attend elementary school and child care.
Since 1979Trusted Source, no cases of polio have reportedly originated in the U.S., although some cases have occasionally occurred due to the virus spreading through international travel.
First polio case in the U.S. in almost a decade
On July 21, 2022, the New York State Department of Health (NYSDOH) and Rockland County Department of Health alerted the public to a case of polio in an adult Rockland County resident, making it the first U.S. polio case since 2013.
According to NYSDOH health officials and the Centers for Disease Control and Prevention (CDC), evidence suggests the Rockland County resident contracted polio from someone who had received oral polio vaccine (OPV)Trusted Source — a live version of the polio vaccine no longer administeredTrusted Source in the U.S.
Then on August 4, 2022, NYSDOH reported researchers had found wastewater samples positive for the polio virus genetically linked to the Rockland County resident diagnosed with polio.
According to NYSDOH, as of August 5, 2022, the CDC confirmed the presence of the polio virus in 11 wastewater samples. Officials collected six samples in Rockland County in June and July, and five samples in July from neighboring Orange County, NY.
Is polio occurring in other countries?
On August 10, 2022, the UK Health Security Agency (UKHSA) issued a statement offering all children between the ages of 1 and 9 in London a dose of polio vaccine.
This follows an earlier report of type 2 vaccine-derived poliovirus found in sewage samples from north and east London.
The UKHSA is reportedly working with health officials in New York and Israel, as well as the World Health Organization (WHO), to investigate any relationship between these recent polio detections.
Earlier this year, officials in Israel discovered cases of polio in Jerusalem and other cities.
With these recent findings, many people may worry about a polio outbreak in the U.S. Can you get polio if you are vaccinated? And how can people protect themselves from infection?
Medical News Today recently spoke with medical experts, as well as the NYSDOH, to get some answers to these questions.
Should we worry about a polio outbreak in the U.S.?
Dr. Marny Eulberg is a family physician and board member of Post-Polio Health International. A polio survivor, since 1985 Dr. Eulberg has run a polio clinic, seeing over 1,500 polio survivors. She told MNT that polio anywhere in the world is a potential threat to anyone who has not been fully vaccinated against it.
“The case in New York demonstrates that with our mobile societies polio can be imported into parts of the world that have not seen polio for decades,” she explained.
“Based on earlier polio outbreaks, New Yorkers should know that for every one case of paralytic polio observed, there may be hundreds of other people infected,” New York State Health Commissioner Dr. Mary T. Bassett states.
“Coupled with the latest wastewater findings, the Department is treating the single case of polio as just the tip of the iceberg of much greater potential spread,” she adds.
“As we learn more, what we do know is clear: The danger of polio is present in New York today,” Dr. Bassett continues. “We must meet this moment by ensuring that adults, including pregnant people, and young children by 2 months of age are up to date with their immunizationTrusted Source — the safe protection against this debilitating virus that every New Yorker needs.”
“We are now seeing polio outbreaks in specific communities and among certain individuals who, for some reason or other, are not vaccinated against polio,” said Dr. Waleed Javaid, hospital epidemiologist and director of infection prevention and control at Mount Sinai New York. “Those individuals and communities are at a higher risk of contracting the disease.”
“We are seeing this now because not everyone is vaccinated against polio,” Dr. Eulberg added.
“In this case, the community where this man lived has low vaccination rates against polio, but also against measles — they had a fairly large measles outbreakTrusted Source within the last 5 years. As we have seen with the COVID pandemic, there are many people who are opposed to vaccinations for a variety of reasons. Many younger people have not known anyone who had polio and feel that it is no longer a threat to them or their families and therefore they don’t need to be vaccinated against it.”
– Dr. Marny Eulberg
Can you get polio if you are vaccinated?
According to the CDC, two doses of IPV — the only polio vaccine available in the U.S. since 2000 — offer 90% immunity to all three types of the polio virus, while three doses give a person 99% protectionTrusted Source.
“It is unlikely for a vaccinated person to get polio,” Dr. Javaid told MNT.
Dr. Eulberg agreed, stating the polio vaccines are very, very effective in preventing disease. She said you cannot get polio from IPV.
“But when we were using the live, oral attenuated poliovirus vaccine in the U.S., we learned that for every million doses that were given, about one person might develop acute polio paralysis,” she explained.
“This was/ is termed ‘vaccine-associated’ polio. The individuals most at risk of developing polio after getting the oral vaccine were individuals with immune deficiencies or adults who had not been immunized and changed the diapers of young family members who had received the oral vaccine in the prior month or two,” she further specified.
Dr. Eulberg explained that polio is primarily transmitted by the fecal-oral route similar to that of hepatitis A. “In the instance of an infant developing polio after receiving the oral vaccine, it might have been the first indication that they indeed had an immune deficiency,” she added.