Robert F. Kennedy Jr. told senators he would apologize if data shows vaccines don’t cause autism, but he cited a poorly conducted study to counter the dozens that show they do not.

The man who hopes to be President Donald Trump’s health secretary says he needs to see data showing vaccines are safe, but he dismissed the evidence shown by an influential Republican senator.

Robert F. Kennedy Jr. faced about 3.5 hours of questioning on topics including his past comments on vaccines and abortion during the first of his two confirmation hearings.

In his second day of confirmation hearings, Robert F. Kennedy Jr., President Donald Trump’s pick to lead the Department of Health and Human Services, refused to say that vaccines do not cause autism -- despite a large body of evidence showing there is no link.

Robert F. Kennedy Jr.’s nomination to be the nation’s top health official is uncertain after a key Republican joined Democrats to raise persistent concerns over the nominee’s deep skepticism of routine childhood vaccinations that prevent deadly diseases.

Kennedy’s bid to serve as America’s top health official may be decided by a handful of Republicans, including several senators who questioned him Thursday.

The hearings were packed to capacity with protesters and fans, while the spillover crowd hung out in hallways and overflow rooms.

Kennedy Jr. faced a plethora of tough questions on vaccines, abortion and public health policy during his Senate confirmation hearing Wednesday as President Donald Trump’s pick for secretary of Health and Human Services (HHS).