House Democrats on the Oversight Committee are calling for an urgent briefing with staff from the Centers for Disease Control and Prevention (CDC), demanding answers over recent moves that have taken place among the agency's vaccine advisory panel, ABC News can exclusively report. House Oversight Committee Ranking Member Rep. Robert Garcia and Oversight Subcommittee on Health Care and Financial Services Ranking Member Rep. Raja Krishnamoorthisent a letter on Thursday morningto CDC chief of staff Matthew Buzzelli, expressing concern over the CDC's Advisory Committee on Immunization Practices (ACIP). Recently, Health and Human Services (HHS) Secretary Robert F. Kennedy Jr.removed all 17 sitting members of the ACIPandreplaced them with hand-selected members, some of whom have expressed vaccine-skeptic views. MORE: RFK Jr., CDC panel have been casting doubt on the hepatitis B vaccine. Here's why it's safe During the first meeting with the new members a few weeks later, the ACIPrefused to recommend certain flu vaccineswith thimerosal, said it would beexamining the child immunization schedule-- including whether babies needed to receive the hepatitis B vaccine at birth -- and heard a presentation from "the former president of Secretary Kennedy's anti-vaccine organization," according to a copy of the letter viewed by ABC News. Although not named in the letter, this is in reference to Lyn Redwood, a former president of the Children's Health Defense, a group founded by Kennedy that pursues anti-vaccine causes. "Oversight Committee Democrats write to understand how these appointees were selected, whether their decisions align with science, and what potential conflicts of interest may be compromising our public health system," the letter reads. Garcia and Krishnamoothi also expressed concern over the failure to vote on recommendations for an updated COVID-19 vaccine before the fall, despite the vote initially being listed on the agenda, as well as concern over potential influence from Kennedy beyond selecting new members for the panel. Reportedly, a CDC document was removed from the meeting materials for last month's ACIP meeting before the meeting began. The document allegedly found there was no link between the preservative thimerosal in flu vaccines and autism. Kennedy has previously, and falsely, suggested a connection between the two. The congressional members called for a briefing with CDC staff by Thursday, July 17, and certain information and documents by Thursday, July 24. These include: communications and documents related to the ACIP meeting held last month and the selection of the new ACIP members; a detailed description of how and why each member was selected; and communications between any individual at HHS or CDC with any of the seven new members between Jan. 20 and June 25 MORE: Experts warn RFK Jr. is unraveling the system that kept vaccines safe "Secretary Kennedy has repeatedly put his personal political ideology ahead of public health and safety, without regard for genuine scientific evidence," the letter reads. "His efforts have drawn serious criticism from even Republican public health experts … These attacks on the independent scientific public health process will make Americans sicker." The letter comes just a few days after major medical organizations, including the American Academy of Pediatrics,filed a lawsuit against the HHS and Kennedyover what they called "unlawful, unilateral vaccine changes." The organizations accused the HHS and Kennedy of intentionally taking away vaccines, such as the COVID-19 vaccine, and unjustly replacing the entire ACIP.