ABSTRACT
This chapter discussed the 2/6-VLP and VP6 DNA vaccines that failed to confer any protection in Gn pigs. These vaccines were tested in mice prior to the Gn pig studies and were reported to confer high protection against murine virus shedding. There are numerous reports of protective immunity against rotavirus infection in mice induced by various routes of inoculation using different forms of rotavirus antigen (e.g., live or inactivated, homologous or heterologous rotavirus; recombinant rotaviral proteins or VLPs; and DNA plasmids). However, the protective efficacy of the 2/6-VLP or VP6 DNA plasmid rotavirus vaccines in the adult mouse model (protection against infection) did not predict the lack of protective efficacy against rotavirus disease in the neonatal Gn pig model. To protect neonatal pigs (and human infants) against rotavirus diarrhea may require much higher levels of intestinal IgA antibodies or IgA antibodies with neutralizing specificity against VP4 and/or VP7 than to protect adult mice against rotavirus infection. When combined with a live oral attenuated HRV priming dose, 2/6-VLP and VP6 DNA vaccines functioned as effective boosters to enhance the protection rate.
