The above discussed results showed that Nc/Nga mice inoculated with VACV strain WR fulfill characteristics of a model of eczema vaccinatum independently of OVA sensitization, suggesting that they are the model of choice for such studies. In contrast, in Balb/c and C57Bl/6J mice, sensitization with OVA was necessary. Nevertheless, Balb/c mice sensitized with OVA and other allergens have been successfully used in studies of EV. MVA, attenuated VACV that does not PF-573228 replicate in mammals, seems to be a safe option for inducing anti poxviral immunity, especially in a topics that cannot be vaccinated with replicating VACV. Previously, MVA effect was demonstrated in a topic, OVA-sensitized Balb/c mice, in which MVA immunization prevented the appearance of lesions after a subsequent inoculation of WR into the skin. MVA also seems to induce good immune responses in blood tests in human a topics, but the efficacy cannot be tested in vivo. Therefore, we used the atopic Nc/Nga mice for testing efficiency and safety of MVA immunization against a lethal poxviral challenge and compared it with Dryvax, the old smallpox vaccine associated with post-vaccination complications. We have used immunization with a single dose of administered MVA and a single dose of t.d. administered Dryvax. The immunization with Dryvax protected 100% of mice, but it should be emphasized that these mice revealed relatively large skin lesions and formation of satellite lesions after the virus inoculation, further confirming an increased risk of development of eczema vaccinatum in AD individuals. On the other hand, immunization with TCS 359 non-replicating MVA that is safe even for a topic and that did not lead to development of any lesions detectable one week after immunization, led to a substantial, but incomplete survival of the immunized animals. The number of MVA-immunized animals that succumbed to the lethal challenge with WR was too low to indicate any significant differences between the t.d. and i.m. immunizations.However it appears that most animals that probably did not develop any detectable levels of antibodies after a single dose of MVA were still able to successfully defeat the lethal challenge with VACV strain WR.