Antibody responses and protection stimulated by sequential oral-parenteralimmunization of mice with rotavirus

Antibody responses and protection against shedding following oral challenge with murine rotavirus (EDIM) were determined in mice after sequential oral -parenteral immunization. Oral immunization of 4-day-old BALB/c mice with l ive, heterologous rotavirus (RRV) stimulated serum rotavirus Ige but little serum or intestinal rotavirus IgA and small but significant (P < 0.001) re ductions in EDIM shedding. Intraperitoneal immunization with inactivated ED IM at 29 days of age had similar effects. Sequential oral-parenteral immuni zation under these conditions stimulated small but significant (P < 0.001) increases in both rotavirus IgG and IgA titers and reduced shedding (P < 0. 001) compared to individual immunizations. However, these responses were es sentially additive, indicative of separate inductive/effector sites for muc osal and systemic immunity. (C) 1999 Elsevier Science Ltd. All rights reser ved.