"Any possible doubts, whether or not well founded, about the safety of the vaccine cannot be allowed to exist."

Page 255, Fed. Register Vol. 49, No. 107, Friday, June 1 1984.

https://www.govinfo.gov/content/pkg/FR-1984-06-01/pdf/FR-1984-06-01.pdf

However, although the continued availability of the vaccine may not be in immediate jeopardy,

any possible doubts, whether or not well founded, about the safety of the vaccine cannot be allowed to exist

in view of the need to assure that the vaccine will continue to be used to the maximum extent consistent with the nation’s public health objectives.

Accordingly, because of the importance of the vaccine and of maintaining public confidence in the immunization program

that depends on it, good cause exists to issue these amendments as a final rule effective immediately. The fact that the

amendment relieves a restriction also justifies making the rule effective immediately.