Bill Cassidy (R-LA) Medical Background: A gastroenterologist.
Vaccine Views: Historically, Cassidy has been a proponent of vaccines, citing his medical career as shaping his support. He notably voted to confirm Robert F. Kennedy Jr. as HHS Secretary in early 2025 based on what he said were Kennedy's promises not to undermine federal vaccination programs.
Recent Actions: At a September 2025 hearing, Cassidy grilled Kennedy on vaccine policy, accusing him of breaking his promises. Cassidy specifically raised concerns over Kennedy's moves to cancel mRNA vaccine research funding, replace a vaccine advisory panel, and limit access to COVID-19 vaccines for certain groups.
John Barrasso (R-WY)
Medical Background: An orthopedic surgeon.
Vaccine Views: A vocal supporter of vaccines. In a 2020 op-ed, he urged people to get the COVID-19 vaccine, citing personal responsibility and public health.
Recent Actions: At the September 2025 hearing, Barrasso joined Cassidy in questioning Kennedy's actions, stating he was "deeply concerned" that Kennedy was undermining vaccines. He noted the turmoil at the CDC under Kennedy and expressed worry that safe, proven vaccines could be in jeopardy.
Rand Paul (R-KY)
Medical Background: An ophthalmologist.
Vaccine Views: Paul is a proponent of medical freedom and has expressed skepticism of government-mandated vaccinations, though he states he is not anti-vaccine. In the past, he has made comments connecting vaccines to "profound mental disorders," an assertion with no basis in medical research. He has also questioned the effectiveness of some vaccines.
Recent Actions: Paul has previously criticized COVID-19 vaccine mandates and has clashed with former top infectious disease expert Dr. Anthony Fauci. He has suggested taking fewer vaccine doses and has cited the risk of myocarditis.
Roger "Doc" Marshall (R-KS)
Medical Background: An OB-GYN.
Vaccine Views: Supported the use of vaccines in the context of the COVID-19 pandemic, but has also raised concerns over vaccine policies.
Recent Actions: In March 2025, Marshall questioned a nominee for the National Institutes of Health regarding vaccine data transparency. At the September 2025 Kennedy hearing, he raised concerns over COVID-19 vaccine data and the policies of HHS, but his critiques have been less direct than Cassidy's and Barrasso's.
