A nurse administers polio vaccine drops to a young Palestinian patient at the Nasser hospital in Khan Yunis in the southern Gaza Strip on Saturday amid the ongoing conflict between Israel and the Hamas militant group. Jihad Al-Sharafi/AFP via Getty Images hide caption
Palestinian children are sitting on a street flooded with sewage water in Deir el-Balah, in the central Gaza Strip, on July 23. Polio was detected in multiple samples of Gaza's wastewater a week ago and now infectious disease experts suspect there are mild cases of the disease already in the population. Majdi Fathi//NurPhoto via Getty Images hide caption
Paul Alexander, who held a Guinness World Record for living the longest with the help of an iron lung, has died. Here, medical staff stand among iron lung machines in an emergency polio ward at Haynes Memorial Hospital in Boston, Mass., on Aug. 16, 1955, when the city's polio epidemic hit a high of 480 cases. AP hide caption
A health worker administers a measles vaccine during a vaccination drive, prompted by a measles outbreak, in Navi Mumbai, India, in December 2022. A new UNICEF report finds that India has the world's largest number of children with zero doses of childhood vaccines: 2.7 million Bachchan Kumar/Hindustan Times via Getty Images hide caption
Do some people have built-in protection against a COVID infection? Laura Gao for NPR hide caption
FILE - This 2014 illustration made available by the U.S. Centers for Disease Control and Prevention depicts a polio virus particle. The polio virus has been found in New York City's wastewater in another sign that the disease, which hadn't been seen in the U.S. in a decade, is quietly spreading among unvaccinated people, health officials said Friday, Aug. 12, 2022. AP hide caption
Minda Dentler handcycling at mile 32 of The Kona Ironman in Hawaii, 2013. She's the first female wheelchair athlete to complete the Ironman World Championship. When she was an infant, her legs were paralyzed by polio. "I wish all people who may be on the fence about vaccination could really meet me," she says. "I'm a reminder to families that they should vaccinate their children." Kevin Charboneau hide caption
This carefully-worded and designed infographic from Rockland County, NY describes — in English, Spanish, Haitian Creole, and Yiddish — what polio is and that immunization is the best way to protect yourself and others. Ari Daniel for NPR hide caption
This 2014 illustration made available by the U.S. Centers for Disease Control and Prevention depicts a polio virus particle. Sarah Poser, Meredith Boyter Newlove/CDC via AP hide caption
A health worker gives a polio vaccine to a child in Karachi, Pakistan, on May 23. British health authorities on Wednesday said they will offer a polio booster dose to children aged 1 to 9 in London, after finding evidence the virus has been spreading in multiple regions of the capital. Fareed Khan/AP hide caption
A Centers for Disease Control and Prevention scientist works with polio virus material. The first case of polio in nearly decade was detected in a New York patient Thursday. The individual was unvaccinated and likely contracted the virus from an individual outside of the country. James Gathany/CDC hide caption
This 2014 illustration made available by the Centers for Disease Control and Prevention depicts a polio virus particle. On July 21, 2022, New York health officials reported a polio case, the first in the U.S. in nearly a decade. Sarah Poster and Meredith Boyter Newlove from the CDC via AP hide caption
Aerial view of the Beckton Sewage Treatment Works in London. Between February and May, U.K. scientists found several samples containing closely related versions of the polio virus in wastewater at the plant. mwmbwls/Flickr hide caption
A child receives a polio vaccine in Kampala, Uganda, on Jan. 14, 2022. Nicholas Kajoba/Xinhua News Agency via Getty Images hide caption