The effects of immunization with r-voraxin on tick feeding
parameters are summarized in Table 2. After three times of
immunization, sera obtained from two vaccinated rabbits reacted
with the r-voraxin antigen by Western blot analysis (using
1:1000 diluted serum) before the tick-challenge. At the time of
tick infestation, IgG titers, as determined by ELISA on serum from
immunized and control rabbits, reached 0.668 (mean value of two
rabbits) and 0.063, respectively. In the vaccination trial, 16/60
female ticks (26.7% of ticks fed on vaccinated rabbits) and 15/30
female ticks (50.0% of ticks fed on control rabbit) did not attach on
the rabbit ear or died within the initial 24 h after the introduction
of ticks onto the rabbit ears. These ticks were excluded from the