President Trump’s pick for surgeon general, Casey Means, is in jeopardy, as at least four Republican senators have expressed misgivings over her medical qualifications, views on vaccines, and some dubious advice she’s given as a wellness influencer, according to reporting from The Washington Post.

Senators Bill Cassidy (R-Louisiana), Susan Collins (R-Maine), Lisa Murkowski (R-Alaska), and Thom Tillis (R-North Carolina) all expressed concern about her potential role in a confirmation hearing last month and appear to remain doubtful. Just one of those senators may be enough to block her nomination from advancing beyond the Senate Health committee.

Means, who was nominated more than 10 months ago, is known as a prominent wellness influencer within the Make America Health Again movement and a close ally of anti-vaccine Health Secretary Robert F. Kennedy Jr., who started it. In the hearing, senators pressed Means on her views on vaccines, including shots against the flu and measles and a dose of hepatitis B vaccine for newborns. She largely dodged the questions, refusing to explicitly recommend the life-saving shots and avoided overtly contradicting Kennedy’s anti-vaccine views and misinformation.

Afterward, Senators Collins and Murkowski both said they still had questions. Murkowski also said she had “strong reservations” about Means’s nomination and that, as of last week, that opinion hadn’t changed, according to the Post.

Cassidy, who is the chair of the Senate Health Committee and a strong advocate for vaccines, also pressed Means on her views on immunizations at multiple points during the hearing. Cassidy cast a key vote to confirm Kennedy as health secretary after Kennedy made promises not to impose certain anti-vaccine changes—promises Kennedy has largely broken. Though Cassidy has not indicated how he’ll vote on Means’s nomination, he is seen by those in MAHA as being responsible for her holdup. When the Post asked him about the status of the nomination, Cassidy responded only, “no change.”