First U.S. polio case in nearly a decade reported

Health officials from Rockland County New York reported Thursday that an unvaccinated adult contracted the virus. Officials said the patient had a vaccine-derived strain of the virus, likely contracted from someone who received a live vaccine overseas. The patient is also experiencing paralysis, according to authorities, but is no longer contagious. Officials are trying to determine if anyone else has been infected.

What is a “live vaccine”? There are two types of polio vaccines. Inactivated vaccines, which are the type given in the U.S., are administered in four shots across 6 years to most children. Live vaccines are administered to children as drops in the mouth in some other countries. According to the U.S. Centers for Disease Control, around 93 percent of children in the United States have received at least three shots of the inactivated virus.

Dig deeper: From the WORLD archives, read Emily Belz’s article about the growing doubts about vaccines among religious communities.