Poliovirus microbes in red.
Illustration: PGN

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What you need to know

  • Polio is a vaccine-preventable infectious disease that can cause viral meningitis, paralysis, and death.
  • Parents should make sure their kids have received all required doses of the vaccine.
  • If you are fully vaccinated against polio, the risk of getting infected is negligible, though some New Yorkers should receive a single, lifetime booster dose.

New York Gov. Kathy Hochul declared a state of emergency on Friday over the growing polio outbreak in an effort to boost vaccination rates. The emergency declaration allows pharmacists, midwives, and EMS workers to administer the vaccine.

New York began monitoring wastewater for polio after a man in Rockland County, a northern suburb of New York City, was diagnosed with paralytic polio in July. Three weeks later, health authorities announced that polio had been detected in New York City wastewater, suggesting that the virus was already circulating in the community. Since then, the virus has been detected in wastewater from four counties in the New York metro area—Rockland, Orange, Sullivan, and Nassau—in addition to the city itself.

The reemergence of polio in the U.S. adds to Americans’ health anxieties as the country deals with two public health emergencies: COVID-19 and monkeypox. But the three viruses are very different, and individuals who are fully vaccinated against polio have a negligible chance of getting infected.

What is polio?

Polio is a highly infectious disease that most commonly affects kids under age 5. Although many people who get infected do not show symptoms, about one in 25 will get viral meningitis, and one in 200 will become paralyzed. As with COVID-19, people who are asymptomatic can still spread polio. The disease has no cure but is preventable through vaccination.

Why is the detection of polio in New York City concerning? 

Prior to the Rockland County case, the U.S. hadn’t detected a polio case since 2013. The last confirmed case in New York state was in 1990. 

The reemergence of polio in New York City is concerning because the virus is very contagious among unvaccinated individuals. Public health officials are also worried about the dip in routine vaccination rates over the past few years, especially as health services were disrupted during the pandemic.

Officials say the identification of a single polio case indicates that there may be several hundred more going undetected. Scientists often look at wastewater data for early signs of viral transmission, a strategy that’s been used throughout the COVID-19 pandemic. The discovery of the virus in the wastewater of several New York counties further suggests that it’s already spreading in the community. 

Should I be worried about polio where I live?

If you are unvaccinated against polio or did not finish the immunization series, you are at risk of infection and should talk to your doctor. Unvaccinated individuals in the New York metropolitan area should get their vaccinations as soon as possible since transmission is likely already occurring in the region.

Most U.S. adults were immunized against polio as children. If you are vaccinated against the virus, you do not need to worry. A three-dose course of the vaccine provides at least 99 percent protection. However, some vaccinated New Yorkers should get a single, lifetime booster shot. Consider a booster if you may have been in contact with an infected individual, if you are a health care worker in an area where the virus has been detected, or if you may be exposed to wastewater due to your job.

It’s also crucial for parents to make sure that their kids have been immunized. Children should receive four doses of the vaccine, with the first dose at 6 weeks through 2 months, the second at 4 months, the third at 6 to 18 months, and the fourth at 4 to 6 years. Unvaccinated individuals older than 4 years only need three doses of the vaccine.