Influence of Formulation on the Efficacy of Experimental Oil-Emulsion Newcastle Disease Vaccines

Publisher Website
Google Scholar
Abstract
Experimental oil-emulsion vaccines (21) with different emulsifier contents, aqueous:oil ratios and antigen concentrations were compared by immunization of 4 wk old chickens. Vaccines that contained oil-phase (Arlacel 80) and aqueous-phase (Tween 80) emulsifiers induced 2- to 4-fold higher hemagglutination-inhibition titers than vaccines with only the oil-phase emulsifier. The emulsion vaccines containing both emulsifiers were also more stable at 37.degree. C and less viscous than those containing only the oil-phase emulsifier. Vaccines that had different aqueous:oil ratios and contained different quantities of alloantoic fluid antigen (1.2-50% of the vaccine volume) induced similar challenge protection; hemagglutination-inhibition titers were proportional to the amount of antigen added. Vaccines that had different aqueous:oil ratios but contained equal amounts of antigen induced similar hemagglutination-inhibition titers and similar protection against challenge.