Most DHHS Secretaries were politicians; many were lawyers; a few were doctors
Complaining that RFK, Jr. does not have a medical degree is hypocritical
https://www.u-s-history.com/pages/h1252.html
Here are all the Secretaries of the Department of Health, Education and Welfare (1953-1979) and the Secretaries of the Department of Health and Human Services (after 1979, when Education got its own department)

Here are the professions of the last ten Secretaries of the DHHS:
Becerra: lawyer, politician
Azar: lawyer, Pharma CEO
Price: physician
Burwell: bureaucrat, worked for BMGF
Sibelius: politician, lobbyist
Leavitt: politician
Thompson: politician
Shalala: politician
Sullivan: physician
Bowen: physician, politician