CDC: The US is a country with circulating vaccine-derived polio

The Centers for Disease Control and Prevention (CDC) announced today that the poliovirus found in New York state meets World Health Organization (WHO) criteria for circulating vaccine-derived poliovirus (cVDPV). This announcement comes from a single case of paralytic polio in an unvaccinated adult in Rockland County, NY, as well as virus found in multiple sewage samples from communities near the patient’s home. The cVDPV declaration means polio continues to be transmitted in Rockland County, NY and the surrounding areas.

Back in August, the CDC sent a small team of federal investigators to New York State to investigate.

The only reported case of polio is an unvaccinated 20-year-old man who contracted the virus. The person is said to have suffered paralysis. No further information is available on the patient’s condition.

This past weekend, New York Gov. Kathy Hochul declared a state of emergency after a case of paralytic polio was identified. The emergency declaration noted that “Local health departments are actively responding to the poliovirus outbreak by assisting in investigations, contact identification and surveillance, administering vaccines to exposed contacts and concentrated current high-risk populations, and education and outreach… The state government must support local communities, Support communities and counties in their efforts to facilitate and implement immunization and testing for poliovirus and prevent further spread of the disease.”

This is the first case here in the United States since 2013. The last case that originated here was in 1979. Polio can originate from different countries and travelers can bring it back to the United States.

And genetically related polioviruses were detected in sewage samples collected in April, May, June, July and August 2022 in the Orange, Rockland and Sullivan counties of New York.

The United States now joins a list of about 30 other countries where cVDPVs have been identified. Circulating vaccine-derived poliovirus occurs when local immunity to poliovirus is low enough to allow prolonged transmission of the originally attenuated virus in the oral polio vaccine.

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 is important to note that cVDPVs are not caused by a child receiving the polio vaccine. The oral polio vaccine has not been used or approved in the United States since 2000, but continues to be used in some countries.

As part of a larger investigation, CDC is working with WHO, the Pan American Health Organization (PAHO), and other international public health partner organizations to study wastewater samples outside the United States. The patient’s virus genetic sequences from Rockland County, NY, and sewage samples collected in New York have been linked to sewage samples in Jerusalem, Israel, and London, UK, suggesting community transmission. The viral sequences from the patient and from three effluent samples contained enough genetic alterations to meet the definition of a vaccine-derived poliovirus (VDPV).

“Polio vaccination is the safest and best way to combat this debilitating disease and it is imperative that people in these communities who are unvaccinated immediately become polio vaccinated up to date,” José R. Romero, MD, director of the National Center for CDC Immunization and Respiratory Diseases, said in a statement. “We cannot stress enough that polio is a dangerous disease for which there is no cure.”

CDC said no additional cases of polio have been reported in the United States and today’s update does not affect current CDC recommendations for polio vaccination for children or adults.