Fig. 9.

Protective efficacy of rAPMV3 immunization after intramuscular challenge. NDV challenge virus shedding titer determined by TCID₅₀ assay in oral and cloacal swabs 3, 5, and 7 days after intramuscular (I/M) challenge of chicken groups immunized with rAPMV3s. No virus was detected in the rAPMV3-F-, rAPMV3-HN-, rAPMV3-F-plus-rAPMV3-HN-, and LaSota-vaccinated groups 3 days after intramuscular challenge (a). Furthermore, no virus shedding was observed 5 days after intramuscular challenge, except for cloacal shedding in the rAPMV3 group (b). A similar pattern of virus shedding was observed 7 days after intramuscular challenge (c). The percent survival of rAPMV3-immunized chickens following NDV challenge by intramuscular routes is shown in panel d. All of the chickens in the unvaccinated control group died by day 5 after intramuscular challenge. All of the chickens in the rAPMV3 empty vector, rAPMV3-F, rAPMV3-HN, rAPMV3-F plus rAPMV3-HN, and LaSota groups survived after intramuscular challenge. Statistical differences between the groups were determined by the log-rank test with P < 0.0001.