Fig. 3.

Vaccine potency of recombinant viruses. (a) Groups of five C57BL/6 mice were vaccinated by i.d. inoculation in both ear pinnae with 10⁴ p.f.u. of the indicated viruses and challenged i.n. 1 month later with 5 × 10⁶ p.f.u. of wild-type WR and the resulting weight change was monitored daily. (b) Groups of five BALB/c mice that were vaccinated i.n. with 5 × 10³ p.f.u. of the indicated viruses were challenged i.n. 6 weeks later with 5 × 10⁶ p.f.u. of wild-type VACV WR and the resulting weight change was monitored daily. Data are expressed as the percentage ± SEM of the mean weight of the same group of animals on day 0. Statistical analyses for data on the days p.i. indicated are in the tables on the right hand side and were performed using the Student’s t-test. All experiments were conducted at least twice and the data shown are representative.