Review ArticleImmunologic correlates of protection induced by vaccinationPLOTKIN, STANLEY A. MDAuthor Information From Aventis Pasteur, Doylestown, PA; and the Department of Pediatrics, University of Pennsylvania, and Wistar Institute, Philadelphia, PA. Accepted for publication Oct. 10, 2000. Address for reprints: Stanley A. Plotkin, M.D., Aventis Pasteur, 4650 Wismer Road, Doylestown, PA 18901. Fax 215-297-9323; E-mail Stanley.Plotkin@Aventis.com. The Pediatric Infectious Disease Journal: January 2001 - Volume 20 - Issue 1 - p 63-75 Buy Abstract Vaccine design and licensing depend on the choice of protective antigens and the demonstration of their efficacy. Ideally efficacy correlates with some measurement of immune response, although occasionally the correlation is weak and in the case of some vaccines uncertain. This paper attempts to review what is known about correlates of vaccine-induced protection. Although mucosal and cellular immune responses are clearly important to protection by some vaccines, most vaccines licensed today depend for their efficacy on serum antibodies. Particular levels of antibodies can be identified that confer protection most of the time. A condition for the efficacy of antibodies is functionality, i.e. their ability to kill or inactivate pathogens. The immune system is redundant, and the different types of responses to vaccines act synergistically. © 2001 Lippincott Williams & Wilkins, Inc.