Table 1.

Antiviral antibody responses to whole homologous H3N2 or heterologous H5N1 viruses after vaccination with H3N2 virus

Coating antigenTreatmentVaccination routeaAntiviral antibody titerb
Serum IgGLung IgGSerum IgALung IgA
Whole H3N2LT(R192G)i.n.<250<25<250<25
H3N2i.n.1 × 106 25,60016,0006,400
H3N2 and LT(R192G)i.n.4 × 106 102,40064,00025,600
H3N2s.c.1 × 106 1,600250<25
H3N2 and LT(R192G)s.c.1 × 106 6,400250<25
Whole H5N1LT(R192G)i.n.<250<25<250<25
H3N2 and LT(R192G)i.n.256,0006,4004,0006,400
H3N2 and LT(R192G)s.c.64,000400250<25
  • a Mice received three inoculations at weekly intervals of 20 μg of formalin-inactivated H3N2 (X-31) virus plus 2 μg of LT(R192G) or 2 μg of LT(R192G) alone. Two weeks after the final vaccine boost, mice from each vaccine and LT(R192G) control group were euthanatized for serum and lung wash collection. Samples pooled from five mice per group were used.

  • b Titers are expressed as the highest dilution of serum having a mean optical density at 405 nm greater than the mean plus two standard deviations of similarly diluted LT(R192G) control serum.