<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A substance added to a vaccine to improve the immune response so that less vaccine is needed.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Substances used in vaccines to enhance the ability of antigens to elicit an immune response.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>