Comparative evaluation on mouse nasal immunogenicity of arylmethane-, xanthene-, quinone-imine-, and acridine-dye-inactivated Sendai virus vaccines.

Twenty-seven kinds of organic dye-inactivated Sendai virus vaccines were prepared by treatment in dark at 23 C for 2 months or more, and selected with the high HA titers as a guide. Their nasal immunogenicities were examined in mice by contact infection and immunofluorescent method, and the relative merits of the dye-inactivants were determined. The strongest protection was elicited with acriflavine-, auramine O-, eosin Y-, neutral red-, night blue-, patent blue V-, thymol blue-, uranin-, and xylene cyanol FF-treated vaccines. Middling protective efficacy was induced by use of erio green B-, malachite green-, methyl green-, proflavine-, pyronin B-, and thionin-inactivated vaccines. Dye-inactivated vaccines that resulted in the weakest protection were Bindschedler's green-, bromothymol blue-, erythrosin B-, ethyl violet-, gallein-, light green SF yellowish-, methyl violet-, new methylene blue N-, phenol red-, rhodamine 6G-, spirit blue- and victoria blue B-treated ones. Serum HI titers developed by nasal vaccination were variable, and rose still more in most vaccinated groups postexposure. Elicitation of the most effective nasal immunogenicity in dye-inactivated vaccines appeared to depend on selective modification of capsid protein or ribose in viral core with dyes possessing definite functions, despite the different molecular structures.