Mr. Kennedy has privately expressed interest in having Mr. Siri serve in the Health and Human Services Department’s top legal job, general counsel.

He did not mention the petitions he has lodged on behalf of ICAN with the Food and Drug Administration, asking regulators to withdraw or suspend approval of vaccines not only for polio, but also for hepatitis B.

Like Mr. Kennedy, Mr. Siri insists he does not want to take vaccines away from anyone who wants them. “You want to get the vaccine — it’s America, a free country.” he told Arizona legislators last year after laying out his concerns about the vaccines for polio and other illnesses.

“She has come to believe that many of the run-of-the-mill complaints general practitioners see in their day-to-day, which they may be tempted to discount as psychosomatic or “sensitive” or hypochondriacal, do have a biological basis — probably far more than anyone knows or thinks.”