Abstract

CONTENT ALERTS Receive: RSS Feeds, eTOCs, free email alerts (when new articles cite this article), more» Information about commercial reprint orders: http://jb.asm.org/site/misc/reprints.xhtml To subscribe to to another ASM Journal go to: http://journals.asm.org/site/subscriptions/ THE ANTIVIRAL ACTIVITY OF NEWCASTLE DISEASE IMMUNE SERA1 R. P. HANSON, NANCY S. WINSLOW, C. A. BRANDLY, AND ELIZABETH UPTON Departments of Veterinary Science and Agricultural Bacteriology, University of Wisconsin, Madison, Wisconsin Received for publication July 17, 1950 The diagnostic value of the hemagglutination inhibition test for Newcastle disease has been established for some years (Brandly et al., 1946). The question of the relationship of the hemagglutination inhibition activity (HI) of immune sera to virus-neutralizing activity (SN) or to the refractivity of the host to challenge infection is still one of both fundamental and practical importance. Data have been gathered in this laboratory that make it difficult to ascribe the various expressions of antiviral activity to a single antibody. EXPERIMENTAL METHODS AND RESULTS One strain of Newcastle disease virus (NDV), a chicken-embryo-adapted culture of low virulence for chickens, designated KD-NJ-1945, was used in both the living and killed state, in all the original experiments. The living inocula consisted of infected allantoamnionic fluids having an HI titer