Rocky Mountain spotted fever vaccine

n.
  1. A vaccine containing a suspension of inactivated Rickettsia rickettsii prepared by growing the microorganisms in the yolk sac of fowl eggs, used to immunize against Rocky Mountain spotted fever.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.