The Ready Reserve Corps of the US Public Health Service already existed under 42 USC 204.
What’s unusual about the amendment to it is that it converted all Reserve Officers serving on active duty as of the enactment date into Commissioned Officers of the Public Health Service, effectively being appointed as Commissioned Officers by legislative fiat rather than, as the law otherwise requires, appointed by the President with the Advice and Consent of the Senate.
Context, context!
Also, can't download the huge Senate Acrobat file -- times out for me on dialup. It must be monstrously big.