Health Secretary Robert F. Kennedy Jr. plans to nominate seven new advisers to a scientific committee that recommends which vaccines Americans should take and when, according to two former federal officials with knowledge of the matter.

The panel, the Advisory Committee on Immunization Practices, wields enormous influence. Insurance companies and government programs like Medicaid are required to cover the vaccinations it recommends.

After Mr. Kennedy’s confirmation hearing, Senator Bill Cassidy, Republican of Louisiana, said he had received assurances that Mr. Kennedy would “maintain the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices without changes.”

In June, Mr. Kennedy fired all 17 members of the panel, asserting without evidence that the committee members were “plagued with persistent conflicts of interest,” even though they had been carefully vetted for such conflicts.

Two days later, he appointed eight doctors and researchers, half of whom had expressed skepticism of vaccines at some point. (One later stepped down because of financial conflicts of interest.)

Mr. Kennedy has demolished the status quo at the C.D.C., which he once called “a cesspool of corruption.” He fired the agency’s director last week, prompted the resignation of several top officials and has gutted its budget and departments.