Even in the remote Faroe Islands, some children have high levels of perfluorinated compounds in their blood. The chemicals may interfere with the immune system. Stig Nygaard/Flickr hide caption

toggle caption Stig Nygaard/Flickr

Michele Pereira, who questions the schedule of mandatory vaccines, sat with her daughters, Evangeline, 6, right, and Genevieve, 2, at a park in Ashland, Ore., earlier this month. Jeff Barnard/AP hide caption

toggle caption Jeff Barnard/AP

What's in this vial changes from year to year, but the process of creating the flu vaccine remains pretty constant.

Justin Sullivan/Getty Images hide caption

toggle caption Justin Sullivan/Getty Images

A Haitian protester in Port-au-Prince last month spray-paints a wall, equating the UN mission in Haiti (abbreviated here as MINISTA) with cholera.

Thony Belizaire/AFP/Getty Images hide caption

toggle caption Thony Belizaire/AFP/Getty Images

A mother held her baby as she received an experimental malaria vaccine at the Walter Reed Project Research Center in Kombewa in Western Kenya in Oct. 2009.

Karel Prinsloo/AP hide caption

toggle caption Karel Prinsloo/AP

University of Miami pediatrician Judith L. Schaechter gives an HPV vaccination to a 13-year-old girl last week in Miami. Joe Raedle/Getty Images hide caption

toggle caption Joe Raedle/Getty Images

A nurse vaccinates a child against pneumonia at a healthcare center in Managua in January. Nicaragua received pneumococcal vaccines from the GAVI Alliance. ELMER MARTINEZ/AFP/Getty Images hide caption

toggle caption ELMER MARTINEZ/AFP/Getty Images

NPR thanks our sponsors

Become an NPR sponsor