The top US health official administered polio vaccination drops to children in New Delhi on Friday as India marked one year since its last case of the crippling disease.

The milestone is a major victory in the global effort to eradicate polio. If no previously undisclosed cases are uncovered in the coming weeks, India will be removed from the list of endemic countries, leaving only Pakistan, Afghanistan and Nigeria.

US Health and Human Services Secretary Kathleen Sebelius marked the day by ...