The United States meets the World Health Organization’s criteria for circulating vaccine-derived poliovirus after cases were discovered in New York in recent weeks, the Centers for Disease Control and Prevention confirmed.
The United States joins a list of more than 30 nations. Only seven nations outside of Africa are on the list.
“Circulating vaccine-derived poliovirus occurs when local immunity to poliovirus is low enough to allow prolonged transmission of the original weakened virus in the oral polio vaccine,” the CDC said.” As the virus circulates and more genetic changes occur, the virus can regain its ability to infect the central nervous system and cause paralysis. It’s important to note that (circulating vaccine-derived polioviruses) are not caused by a child receiving the polio vaccine. Oral polio vaccine has not been used or licensed in the U.S. since 2000 but continues to be used in some countries.”
The CDC said a paralytic case of polio was reported in Rockland County, New York. The person was not vaccinated, the CDC said. There has also been poliovirus detected in wastewater in several New York counties.
Unlike the polio vaccine distributed in the U.S., which uses inactive strains of the virus, the oral vaccine consists of a mixture of live attenuated poliovirus strains. The oral vaccine is widely used in poorer nations to reduce severe diseases.
However, the oral vaccine can cause illnesses and transmission in some cases.
The CDC said that there is no updated guidance and that the vaccines used in the U.S. continued to be recommended for children or adults.
“I think it is concerning, it is very concerning. I hope for a lot of people this is a wake-up call. I hope for people who are unvaccinated, who have unvaccinated children and friends that this is a wake-up call,” Dr. Daniel Griffin, instructor of clinical medicine at Columbia University, told CNN. “This is really letting everyone know that the poliovirus is here. It's circulating. It's coming up in the wastewater because there are people that are infected with this virus, they are shedding this virus.”