Immunogenicity to native VLPs has been reported previously for one other paramyxovirus namely NDV [49] . In that report, immune response to NDV VLPs was evaluated by primary inoculation of mice intraperitoneally with VLP concentrations ranging between 10 and 40 mg, and a booster dose of 10 mg, without adjuvant. NDV-specific titers by ELISA were high in each mouse in each treatment group. Neutralizing antibody response to 20 and 40 mg of these particles was also detected.