Polio outbreaks regularly sparked panic decades ago, until a vaccine was developed and the disease largely eradicated. Then on Friday, New York City health officials announced they had found the virus in sewage samples, suggesting polio is likely circulating in the city again.
Parents of young children asked themselves the question: maybe for the first time in their lives, and overall for the first time in generations—how worried they should be about polio.
Anabela Borges, a designer who lives in Brooklyn’s Crown Heights neighborhood, said she has friends whose children are unlikely to be vaccinated. Following Friday’s announcement, she said she plans to “call her friends’ attention.”
Ms Borges said she hopes her 7-month-old daughter Ava, who is old enough to have had three of the four vaccines recommended for children, is advanced enough in therapy to be protected. “Polio is really dangerous for babies like her,” Ms Borges said as she and her daughter’s nanny took Ava for a stroll in her stroller.
In New York City, the overall polio immunization rate for children under age 5 is 86 percent, and most adults in the United States were vaccinated against polio as children. Still, in some city zip codes, fewer than two-thirds of children under the age of 5 have received at least three doses, a number that worries health officials.
The state Department of Health said in a statement the discovery of the virus “underscores the urgency for every adult and child in New York to be vaccinated, particularly those in the New York metro area.”
The announcement came three weeks after a man in Rockland County, NY, just north of the city, was diagnosed with a case of polio that left him paralyzed. Officials now say polio has been circulating in the county’s sewage since May.
“The risk to New Yorkers is real, but the defense is so simple — get the polio vaccine,” said Dr. Ashwin Vasan, the New York City Health Commissioner, in a statement. “As polio circulates in our communities, there is simply nothing more important than vaccinating our children to protect them from this virus, and if you are an unvaccinated or under-vaccinated adult, please make a decision to get the vaccine now.”
The spread of the virus poses a risk for unvaccinated people, but three doses of the current vaccine provide at least 99 percent protection against serious illness. Children too young to be fully vaccinated are also at risk, as are children whose parents have refused vaccination or postponed vaccination.
Health officials are concerned that the detection of polio in New York City’s sewage could precede other cases of paralytic polio.
The fight against polio
The highly contagious virus was one of the most feared diseases until the 1950s when the first vaccine was developed.
“Without a relatively massive vaccination campaign, I think it’s very likely that it’s one or more cases in the city,” said Dr. Jay Varma, epidemiologist and former deputy city health commissioner.
Citywide vaccination coverage fell amid the pandemic as visits to pediatricians were postponed and the spread of vaccine misinformation accelerated. Even before Covid’s arrival, vaccination rates for a range of preventable viruses were low enough in some neighborhoods to worry public health officials.
The vaccine used in the United States for the past few decades, while effective at preventing paralysis, is less effective at limiting transmission. Individuals who have been vaccinated can still carry and shed the virus even if they experience no infection or symptoms.
That, epidemiologists say, could mean it will be difficult to eradicate the virus quickly, further underscoring why vaccination is so crucial for protection, a spokeswoman for the state health department said.
Many people who contract polio do not develop symptoms, but some people have a fever or feel sick. dr Bernard Camins, infectious disease specialist and medical director for infection prevention at Mount Sinai Health System, urged doctors to be on the lookout for these symptoms and consider ordering polio testing for under-vaccinated patients.
About 4 percent of those who contract the virus will get viral meningitis, and about 1 in 200 will become paralyzed, according to health officials.
“The problem,” said Dr. Camins, “is if you have one case of paralysis, there can be hundreds of others that are not symptomatic or have symptoms that are unlikely to be identified as polio.”
The poliovirus had previously been found in sewage samples in Rockland and Orange Counties, but Friday’s announcement was the first sign of its presence in New York City.
Neither the city nor the state health authorities provided information about where in the five districts the virus had been detected in the wastewater. State officials said six “positive samples of concern” had been identified in city sewage, two in June and four in July.
The last case of polio found in the United States before Rockland County was in 2013.
Before polio vaccines were first introduced in the 1950s, the virus was a source of fear, particularly during the summer months when outbreaks were most common. Cities closed swimming pools as a prevention tactic, and some parents kept their children indoors.
In 1916, polio killed 6,000 people in the United States and left at least 21,000 more—most of them children—with permanent disabilities. More than a third of the deaths occurred in New York City, where the outbreak caused a delay in the opening of public schools.
An eruption in 1952 paralyzed more than 20,000 people and left many children with iron lungs. Shortly thereafter, the first effective vaccine appeared and the virus began to recede.
Today there are only two countries, Pakistan and Afghanistan, where polio is endemic. It has been kept in check in the rest of the world by the widespread use of vaccines.
Cases outside of these two countries are occurring with some regularity, owing to the oral vaccine used in much of the world. The oral vaccine uses a weakened but live virus. It’s safe, but a person who gets it can transmit the weakened virus to others. (Since 2000, only inactivated polio vaccine has been used in the United States.)
“What we’re seeing is a wake-up call for people who thought poliovirus was just a problem elsewhere,” said Capt. Derek Ehrhardt, an epidemiologist and polio eradication incident manager for the Centers for Disease Control and Prevention.
The virus lives primarily in a person’s throat and intestines and is most commonly spread through contact with feces.
If the weakened virus used in the oral vaccine circulates far enough in communities with low vaccination rates or replicates in someone with a compromised immune system, it can mutate into a virulent form that can cause paralysis, according to the CDC
Outbreaks of such “circulating vaccine-derived poliovirus” have occurred in many countries in recent years. Open sewers and contaminated drinking water can accelerate the spread.
Health officials believe the poliovirus was brought into New York by someone who received the live vaccine in another country or by an unvaccinated person who contracted vaccine-related polio while abroad.
Officials say the virus discovered in the two boroughs north of New York City is genetically linked to the vaccine-derived virus collected from samples in Jerusalem earlier this year, as well as sewage samples in London that will lead to a revaccination campaign there led to polio.
On Friday, the CDC confirmed the presence of poliovirus in 20 sewage samples from Rockland and Orange Counties, all genetically linked to the case of paralytic polio in the Rockland County resident. The counties are next to each other.
Of the 20 samples, two were collected in Rockland County in May, three in June, and eight in July; two were collected in Orange County in June and five in July.
dr Orange County Health Commissioner Irina Gelman said officials assumed each positive sample collected in her county indicated a separate person who was locally infected with the virus, but she added that they awaiting further genetic analysis from the CDC to be sure.
Health officials believe hundreds of people in the area could be infected, she said. The estimate is based on how many people would normally need to have the virus for there to be a single case of paralytic polio, combined with the global increase in cases of vaccine-induced polio and very low vaccine coverage in parts of New York.
“Part of me still hopes that won’t be the case,” she said.
“We’re really operating under a perfect storm scenario,” she added. “We have low vaccination rates for vaccine-preventable diseases in Orange County, particularly in our pediatric population.”
The only case of polio confirmed so far was in a 20-year-old male Ultra-Orthodox Jewish resident of Rockland County, according to several local officials. Orange and Rockland Counties are both home to large numbers of ultra-Orthodox Jews, and anti-vaccination sentiment has spread among some in that community.
A measles outbreak in 2019 also focused on people in the ultra-Orthodox community, although misinformation and low vaccination rates are also more common, Dr. Gelman.
Vaccination rates in Rockland and Orange Counties are well below those needed to prevent the virus from spreading, according to the state Department of Health. Among 2-year-olds, about 60 percent of children in both counties had all three recommended polio shots, state data shows, compared with 79 percent statewide.
Tired of Covid and alarmed by the recent emergence of monkeypox, New Yorkers’ minds turned to a third virus on Friday as they wondered if they were fully vaccinated and if their protection had lasted the decades.
Gregory Ludd, 46, a Crown Heights resident who works as a porter, has six children. They are up to date on their vaccinations, he said, but three of them are under the age of 5.
“I’m scared because we really haven’t heard about polio coming up since we were probably little, little kids,” he said. “But all you can do is trust in God and hope that doesn’t happen to your child.”
Lola Fadulucontributed reporting.