Effects of different adjuvants on rotavirus antibody responses and protection in mice following intramuscular immunization with inactivated rotavirus.

I.m. immunization of mice with inactivated rotavirus particles protects against subsequent infection. To optimize protection, the effects of different adjuvants (QS-21, QS-7, QUIL A, PCPP and RAS) with potential for human use were compared. Twenty-eight days after i.m. immunization with 20 microg of purified, UV/psoralen-inactivated murine rotavirus (EDIM), either with or without adjuvant, BALB/c mice were orally challenged with live EDIM and virus shedding was measured. All five adjuvants stimulated large (P < 0.001) increases in rotavirus antibody, but significant differences were found between adjuvants. The order of rotavirus IgG responses, i.e. no adjuvant < RAS < QS-7 < Quil A < QS-21 < PCPP, was the same as the order of protection except that QS-21 and PCPP were reversed. These results establish the importance of adjuvants during i.m. immunization with rotavirus and identify those with the greatest potential.