The CDC is investigating a case of polio in Rockland...

The CDC is investigating a case of polio in Rockland County — a man who was not vaccinated against the disease. Credit: TNS/Dreamstime

The recent disclosure of a polio case in Rockland County has New York's health department urging those who are unvaccinated, especially children, to get vaccinated against the potentially debilitating disease. It also has served as a reminder that despite the highly effective polio vaccine developed in the 1950s by virologist Dr. Jonas Salk, the polio virus remains a threat.

Polio has been afflicting humanity since ancient times, according to the Centers for Disease Control and Prevention, whose polio website shows an ancient Egyptian tomb painting of a man with a withered leg who's unable to walk without the help of a stick.

Late last month, the state Health Department reported a case of vaccine-derived polio in a man in his 20s in Rockland County. It was the first such case of polio in the United States since 2013. He had developed paralysis, one of the possible effects of the poliovirus that is irreversible.

It’s a strain related to a weakened, live poliovirus in the oral polio vaccine, which is no longer used or licensed in the United States, but is elsewhere, primarily in the developing world. It’s not an ideal vaccine due to rare side effects in the vaccinated person, such as paralysis in 1 in 750,000 recipients, and the possibility the virus can infect others who are unvaccinated or undervaccinated. This strain of polio is causing the most new infections worldwide. The vaccine now used in the United States, Trivalent, is a modified version of what was originally developed by Salk.

The man with paralysis in Rockland was unvaccinated but apparently caught it from someone who had gotten the oral vaccine either outside the United States or from someone who came in contact with such a person.

Based on the timing of the onset of the man’s paralysis, he almost certainly got infected in the United States, said Dr. Walter A. Orenstein, a former top CDC official and director of the Emory University Program on Vaccine Policy and Development in Atlanta.

On Aug. 4, the state Health Department said that the poliovirus has now been detected in wastewater samples in several locations in Rockland and Orange counties.

Among children who are 2 years old who have received three polio immunizations, Orange with 58.7% and Rockland with 60.3%, have among the state's lowest vaccination rates, the Health Department reports. The state average is 79%; Nassau's is 79.2% and Suffolk's, 79.1%.

The state Health Department says: “All children should get four doses of the polio vaccine, with the first dose given at 6 weeks through 2 months of age, followed by one dose given at 4 months of age, 6 through 18 months old, and 4 through 6 years old.”

For the wild polio virus, there have been 19 cases worldwide so far, 15 in Pakistan and Afghanistan and four in Africa. For the vaccine-associated paralytic polio, there have been 49 cases in seven countries, Orenstein said. As of Tuesday, the Rockland County man’s case had not yet been added to the tally of 49, which was updated Aug. 2 and is maintained by the World Health Organization, Orenstein said.

For now, having been vaccinated in childhood should protect a person from catching polio, but the more common the virus becomes, the more likely it is that the government might recommend that an adult who is at heightened risk, such as a health care worker in contact with a polio patient, get a once-in-a-lifetime booster, Orenstein said.

“It’s possible, because the cases of paralytic polio are the tip of the iceberg of infections. In other words, there’s generally at least a few hundred if not 1,000 or more infections that may have occurred when you see a paralytic case. About 72% of the infections are totally asymptomatic yet they can infect and transmit, and then about 24% have a minor illness” that presents like a cold, Orenstein said.

It destroys the nerves that tell the muscles what to do — and can be deadly if it hits the nerves of the respiratory system. Paralysis is the permanent effect in the vast majority of serious cases.

The recent disclosure of a polio case in Rockland County has New York's health department urging those who are unvaccinated, especially children, to get vaccinated against the potentially debilitating disease. It also has served as a reminder that despite the highly effective polio vaccine developed in the 1950s by virologist Dr. Jonas Salk, the polio virus remains a threat.

What is polio?

Polio has been afflicting humanity since ancient times, according to the Centers for Disease Control and Prevention, whose polio website shows an ancient Egyptian tomb painting of a man with a withered leg who's unable to walk without the help of a stick.

What about the latest known case?

Late last month, the state Health Department reported a case of vaccine-derived polio in a man in his 20s in Rockland County. It was the first such case of polio in the United States since 2013. He had developed paralysis, one of the possible effects of the poliovirus that is irreversible.

What is a vaccine-derived poliovirus?

It’s a strain related to a weakened, live poliovirus in the oral polio vaccine, which is no longer used or licensed in the United States, but is elsewhere, primarily in the developing world. It’s not an ideal vaccine due to rare side effects in the vaccinated person, such as paralysis in 1 in 750,000 recipients, and the possibility the virus can infect others who are unvaccinated or undervaccinated. This strain of polio is causing the most new infections worldwide. The vaccine now used in the United States, Trivalent, is a modified version of what was originally developed by Salk.

The man with paralysis in Rockland was unvaccinated but apparently caught it from someone who had gotten the oral vaccine either outside the United States or from someone who came in contact with such a person.

Based on the timing of the onset of the man’s paralysis, he almost certainly got infected in the United States, said Dr. Walter A. Orenstein, a former top CDC official and director of the Emory University Program on Vaccine Policy and Development in Atlanta.

Where has the virus been detected?

On Aug. 4, the state Health Department said that the poliovirus has now been detected in wastewater samples in several locations in Rockland and Orange counties.

What are the vaccination rates?

Among children who are 2 years old who have received three polio immunizations, Orange with 58.7% and Rockland with 60.3%, have among the state's lowest vaccination rates, the Health Department reports. The state average is 79%; Nassau's is 79.2% and Suffolk's, 79.1%.

What is the recommendation for childhood vaccination?

The state Health Department says: “All children should get four doses of the polio vaccine, with the first dose given at 6 weeks through 2 months of age, followed by one dose given at 4 months of age, 6 through 18 months old, and 4 through 6 years old.”

How many cases of polio have there been so far in 2022?

For the wild polio virus, there have been 19 cases worldwide so far, 15 in Pakistan and Afghanistan and four in Africa. For the vaccine-associated paralytic polio, there have been 49 cases in seven countries, Orenstein said. As of Tuesday, the Rockland County man’s case had not yet been added to the tally of 49, which was updated Aug. 2 and is maintained by the World Health Organization, Orenstein said.

Am I safe from polio in the United States if I was vaccinated as a child?

For now, having been vaccinated in childhood should protect a person from catching polio, but the more common the virus becomes, the more likely it is that the government might recommend that an adult who is at heightened risk, such as a health care worker in contact with a polio patient, get a once-in-a-lifetime booster, Orenstein said.

Could the virus spread elsewhere beyond Orange and Rockland counties?

“It’s possible, because the cases of paralytic polio are the tip of the iceberg of infections. In other words, there’s generally at least a few hundred if not 1,000 or more infections that may have occurred when you see a paralytic case. About 72% of the infections are totally asymptomatic yet they can infect and transmit, and then about 24% have a minor illness” that presents like a cold, Orenstein said.

What does polio do?

It destroys the nerves that tell the muscles what to do — and can be deadly if it hits the nerves of the respiratory system. Paralysis is the permanent effect in the vast majority of serious cases.

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