Robert F. Kennedy Jr. started a tour of Capitol Hill this week to meet with senators who will vote on his nomination as health secretary and to address worries that he might restrict access to vaccines, particularly for polio. “I fully support the polio vaccine,” Mr. Kennedy told a crowd of reporters on Monday. President-elect Donald J. Trump also aimed to preempt any expected inquiries. “You won’t lose the polio vaccine,” Mr. Trump asserted at a news conference that same day. “That won’t occur.” A New York Times analysis of Mr. Kennedy’s public statements over the last few years reveals that he has consistently voiced opinions on the polio vaccine that conflict with the prevailing medical consensus. He proposed that following the introduction of the vaccine, it could have led to a surge in cancers that resulted in significantly more deaths than polio ever caused. He stated that the belief the vaccine led to a significant decrease in polio cases is “a myth” that is “simply not accurate.” His views on the polio vaccine have been questioned following a report in The New York Times on Friday, which stated that Aaron Siri, a lawyer advising Mr. Kennedy during the transition, submitted petitions on behalf of a nonprofit to overturn federal approval of the standalone polio vaccine, IPOL, and to halt the distribution of 13 other vaccines, some of which provide polio immunization. On Monday, Mr. Kennedy’s spokesperson, Katie Miller, shared her thoughts in an email: “Mr. Kennedy thinks the polio vaccine should be accessible to everyone and thoroughly researched.