other cases that haven’t been diagnosed and there are more people infected than we’re aware of.”
Children should receive at least three doses of polio vaccine by 18 months of age, with a fourth dose delivered between ages 4 and 6, according to the U.S. Centers for Disease Control and Prevention.
New York state health officials say they are particularly concerned by neighborhoods where fewer than 70% of children between 6 months and 5 years of age have received at least three doses of polio vaccine.
About 86% of New York City kids have gotten all three doses, but in Rockland County the rate is just over 60%, and in Orange County the rate is just under 59%, state health officials say.
Statewide, nearly 79% of children have received three doses by their second birthday, officials add.
Poliovirus also has been identified in London’s wastewater, and health officials in the United Kingdom have decided to offer polio vaccine boosters to children.
“They’re starting to do that in London. We haven’t said that that’s necessary,” says Dr. William Schaffner, medical director of the Bethesda, Md.-based National Foundation for Infectious Diseases.
“The only time we’ve given boosters in the past is when someone who was vaccinated as a child then decided to travel to some developing country where there was a lot of polio, and we said, OK, to be on the safe side, to be prudent, we’ll give you a booster before you go,” Schaffner shares. “It wasn’t really thought to be necessary, but it was a prudent, extra, easy, safe thing to do.”
How does the polio vaccine work?
Poliovirus lives in the intestinal tract and can be transmitted through stool, so wastewater surveillance is a logical way to track it, says Vincent Racaniello, a professor of microbiology and immunology at Columbia University in New York City.
“These viruses have probably been in the sewage for years,” he shares. “We’ve just never looked for them, and now we started to look because of this case. And I would say the more we look, we’re going to find it all over the U.S., especially in major cities.”
These strains of poliovirus likely entered the United States from people in other countries who have had