New York state health officials alerted Rockland County residents about a confirmed polio case on Thursday. The last naturally occurring case of polio in the U.S. was in 1979. Health officials believe this case might have originated from outside the U.S., which would be the first since 2013. 

The New York State Department of Health (NYSDOH) and the Rockland County Department of Health advised hospitals in the state to be extra vigilant for additional cases. Polio is a viral disease and once the nation's most feared sickness in the 1950s, which caused neurological symptoms, paralysis, or death and has been eradicated since 1979. 

The iconic photo of an infected child with polio in an iron lung mechanical respirator. 

NYSDOH believes the infected person (still no details about the individual's age or if they traveled outside of the country) has a vaccine-derived strain of the virus and got it from someone outside the country. The person is also unvaccinated against polio, NYTimes confirmed. 

In this case, sequencing performed by the Wadsworth Center – NYSDOH's public health laboratory – and confirmed by CDC showed revertant polio Sabin type 2 virus. This is indicative of a transmission chain from an individual who received the oral polio vaccine (OPV), which is no longer authorized or administered in the U.S., where only the inactivated polio vaccine (IPV) has been given since 2000. This suggests that the virus may have originated in a location outside of the U.S. where OPV is administered, since revertant strains cannot emerge from inactivated vaccines. - NYSDOH

Transmission of the virus appears to be through vaccine shedding. The vaccine in question is the oral polio vaccine (OPV), an attenuated (or "live virus") vaccine given to people outside of the US. People who are given active vaccines have the tendency to shed the virus and infect others.  

Parts of the world where OPV is administered are mainly developing countries, such as Afghanistan and Pakistan, and ones in Africa, Asia, and the Middle East. 

Bill & Melinda Gates Foundation has been a big driver of polio vaccine funding. But a 2019 article from Science indicates the decades-long eradication campaign "suffered major setbacks."

Since 2000, only inactivated polio vaccine (IPV) has been given to U.S. children, and since it's inactive or dead, there's no risk of shedding. 

NYSDOH is now requesting those who are "vaccinated but at risk of exposure" to get a "booster." 

Add polio boosters to the expanding listing of vaccines the government is trying to force into the bodies of Americans, including COVID boosters and ones for Monkeypox.