Despite near eradication globally, some experts warn that reduced vaccine coverage could allow the virus to re-enter communities, posing serious health risks.
Here are four things to know:
- Before the polio vaccine was introduced in 1955, the virus paralyzed 20,000 Americans annually, with thousands dying. Because of vaccines, polio cases have dropped; however, the virus still poses a threat if vaccination rates decline.
- Although polio is nearly eradicated, the virus is circulating in countries including Afghanistan and Pakistan. Vaccine-derived polio cases are now a significant concern, especially in areas with lower vaccination rates.
- Polio’s return in the U.S. is unlikely to be as severe as pre-vaccine outbreaks, but localized outbreaks can occur. In 2024, an unvaccinated individual an ultra-Orthodox Jewish community in New York contracted polio, highlighting the risk posed by unvaccinated pockets.
- The inactivated polio vaccine, used in the U.S., effectively prevents paralysis. However, the virus can still circulate if vaccination rates fall, as seen in areas with low coverage.
