Rotavirus is an important cause of morbidity and mortality worldwide and vaccines are currently under development, with clinical trails conducted in humans worldwide. The immune responses in infant BALB/c mice were examined following oral inoculation with murine rotavirus EDIM (2 × 104focus-forming units) and with three CsCl gradient-purified fractions of heterologous simian rotavirus SA11 (standardized at 2 × 106CCID50) that differed in antigen composition: fraction 1 was enriched for double-layered rotavirus particles, fraction 2 for triple-layered particles and fraction 3 consisted mainly of cell components. Diarrhoea and high IgG responses, but marginal IgA responses, were observed after inoculation with all three SA11 fractions. Virus shedding was observed in all EDIM-inoculated mice, but in none of the SA11 -inoculated mice. Rotavirus-specific IgG1: 2a ratios were similar in mice inoculated with EDIM and SA11 fraction 1, but higher for SA11 fraction 3- and lower for SA11 fraction 2-inoculated mice. A higher IgG1:2a ratio indicates a more Th2-like immune response. This undesirable response is apparently mostly induced by inoculation with heterologous rotavirus in the presence of abundant cell-associated and soluble rotavirus proteins, compared with infection with a more purified preparation or with homologous virus. These data show that, following inoculation with a standardized amount of infectious virus, the composition of the fraction influences the outcome of the immune responses significantly.,
Journal of General Virology
Erasmus MC: University Medical Center Rotterdam

Reimerink, J., Boshuizen, J., Einerhand, S., Duizer, E., van Amerongen, G., Schmidt, N., & Koopmans, M., D.V.M. (2007). Systemic immune response after rotavirus inoculation of neonatal mice depends on source and level of purification of the virus: Implications for the use of heterologous vaccine candidates. Journal of General Virology, 88(2), 604–612. doi:10.1099/vir.0.82126-0