How a delay in vaccination could lead to a resurgence of polio

Most American parents don’t think much about polio beyond the time their child is vaccinated against the disease. But there was a time in this country when polio paralyzed 20,000 people in a year, killing many of them.

Vaccines have turned the tide against the virus. Over the past decade, there has been only one case in the United States, linked to international travel.

This could change very quickly if polio vaccination rates decline or if the vaccine becomes less accessible.

Robert F. Kennedy Jr., a longtime vaccine skeptic who could become secretary of Health and Human Services, said the idea that vaccination nearly eradicated polio is “a mythology “.

And while Mr. Kennedy has said he has no plans to take vaccines away from Americans, he has long argued that they are not as safe and effective as claimed.

As recently as 2023, he said batches of an early version of the polio vaccine, contaminated with a virus, had caused cancers “that killed many, many, many, many more people than the polio never did.” The contamination was real, but research never established a link to cancer.