Do you need a polio booster shot? Everything you need to know about polio vaccines.

Adults who doubt they have been fully vaccinated against polio should talk to their doctors about getting additional shots, experts say.

A confirmed case of polio in New York state has renewed a sense of urgency to make sure everyone is fully vaccinated against the potentially fatal virus, said Duke infectious disease expert Dr. Cameron Wolfe.

“We never really worried about that because so many people had been vaccinated effectively that the disease was gone from the U.S. for decades,” Wolfe said. “Until now.”

This is especially true for children who may have fallen behind on their vaccine series during the pandemic.

The New York case, in which an unvaccinated man developed polio-related paralysis, is the first time since 1979 there has been a polio case that originated in the U.S.

The oral polio vaccine (which some may remember as a sugar cube in a paper cub) was replaced in the U.S. with a series of shots in 2000 because of its ability in rare situations to reactivate itself into a form that was infectious.

CDC researchers found that the New York man was infected with a weakened version of the virus that comes from the oral vaccine, which is still used in some countries abroad.

Subsequent wastewater testing in New York found that polio has been circulating locally for up to a year, according to the CDC, which points to many more asymptomatic infections.

“This one single case in New York has shown it can be the canary in the coal mine,” Wolfe said.

New York is not the only place with a recent resurgence in polio. A handful of polio cases in Europe are also raising red flags for global health researchers.

In June, London health officials found evidence that polio was spreading in the wastewater and recently announced that children between 1 and 9 would be offered a booster shot. An unvaccinated 3-year-old in Jerusalem became paralyzed earlier this year from the virus.

A spokesperson for the N.C. Department of Health said North Carolinians should talk with their doctors about their vaccine history and travel plans.

Most people with polio do not feel sick or have minor symptoms, like a fever, headache or limb pain. In rare cases though, polio can cause permanent and irreversible paralysis.

Polio vaccine refresh:

According to the CDC, adults who know they are unvaccinated or who do not have documentation of their vaccination could qualify for three doses spread across several months.

Wolfe said it would be very unlikely for someone to be unvaccinated without knowing it unless they grew up outside of the United States.

“It’s almost been like the foundational vaccine for so many years that it would be an unusual situation for someone not to have it,” he said.

Those who have only partially completed the three-dose series can go to a doctor to have their missing shots. Two doses of the vaccine are about 90% effective at preventing paralysis while the full series is more than 99% effective at preventing polio related paralysis.

Adults who have been fully vaccinated but are at high risk of exposure (e.g. health care workers who care for polio patients, or people traveling to countries like Afghanistan, where polio is still endemic) may qualify for a one-time booster shot.

Risk in North Carolina:

The risk of contracting polio is still very low for North Carolinians — there have been no confirmed cases in the state and the vast majority of people are vaccinated against the virus.

As of 2017, about 88% of young children in North Carolina had received the vaccine series, which is required for children attending public school in the state.

The state is considering adding polio to the wastewater surveillance it already uses to track COVID-19, but there are no immediate plans to start, a spokesperson for the department of health said.

It’s not known exactly how long the vaccine protects against polio, though it’s likely vaccinated people are low-risk for many years after completing the series, according to the CDC.

Wolfe said even though the name ‘polio’ conjures images of iron lungs and paralyzed children, it is very unlikely that these cases will become anything of significance to a wide population.

“It’s appropriate if this is used as a good chance for folks to go back and check vaccine records — there’s no disadvantage in that,” he said. “But it won’t be the calamity that the name invokes.”

Teddy Rosenbluth covers science for The News & Observer in a position funded by Duke Health and the Burroughs Wellcome Fund. The N&O maintains full editorial control of the work.

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